THE  LIBRARY 

OF 
THE  UNIVERSITY 

OF  CALIFORNIA 
LOS  ANGELES 


RETINOSCOPY 

(SHADOW  TEST) 


THORINGTON 


Reviews  of  the 
First  Edition  of 


Thorington's  Retinoscopy, 


From  "The  Medical  Record,"  New  York. 

"This  little  manual  deserves  a  second  edition,  and  will  undoubtedly  pass  through 
many  more.  It  presents  a  clear,  terse,  and  thorough  exposition  of  an  objective 
method  of  determining  refraction  errors  which  is  deservedly  increasing  in  popularity. 
In  our  opinion  the  author  is  amply  justified  in  declaring  that  its  great  value  in  nystag- 
mus, young  children,  amblyopia,  aphakia,  and  in  examining  illiterates  and  the  feeble- 
minded can  not  be  overestimated,  and  we  agree  with  him  in  reminding  those  who 
attempt  retinoscopy,  fail,  and  ridicule  it,  that  the  fault  is  behind  and  not  in  front  of 
the  mirror.  The  book  is  well  printed  and  usefully  illustrated." 

From  "The  Annals  of  Ophthalmology,"  St.  Louis.  Mo. 

"  Retinoscopy  has  come  to  stay.  It  is  not  a  fad,  neither  a  fashion.  It  is  scientific, 
and  withal  so  eminently  practical  in  its  application  as  to  commend  it  to  every  think- 
ing worker  in  ophthalmology.  The  tendency  in  the  medicine  of  to-day  is  toward 
objective  methods.  An  objective  method  must  possess  two  attributes  :  exactness 
and  absolute  independence  of  the  patient's  testimony.  In  addition  to  these  qualities, 
an  objective  method  must,  if  it  is  to  meet  with  general  acceptance,  be  easy  of  applica- 
tion. Ophthalmoscopy  and  ophthalmometry  are  but  relatively  exact  in  refractive 
work,  seeing  which  the  trial-case  has  held  its  supremacy  up  to  date;  nor  would  we 
wish  to  relegate  it  to  the  background.  With  a  patient  whose  testimony  is  trust- 
worthy exact  results  are  thus  obtainable,  but  it  requires  the  most  intelligent  coopera- 
tion on  the  part  of  the  examined.  If,  however,  there  be  but  the  least  departure  from 
the  conditions  essential  to  close  work  with  the  test-lenses,— as,  for  instance,  with  for- 
eigners, illiterates,  children,  partial  amblyopics,  or  mental  astigmatics,— retinoscopy 
stands  ready  to  furnish  a  verdict  from  which  there  can  be  no  appeal,  when  one  has 
learned  to  properly  interpret  the  movements  observed  in  the  pupillary  area.  It  is  to 
the  elucidation  of  these  latter  movements  as  observed  through  a  plane  mirror  at  a 
distance  of  one  meter  that  Dr.  ThoriiiKton  devotes  himself  in  the  volume  before  us. 
The  treatment  of  the  subject  is  so  beautifully  simple  that  one  who  runs  may  read." 

From  "The  Journal  of  the  American  Medical  Association,"  Chicago,  III. 

"  The  author  of  this  well-written  little  book  has  very  satisfactorily  described  the 
most  approved  methods  of  retinoscopy.  The  work  is  especially  valuable  in  that  for  a 
great  part  it  details  the  results  of  personal  investigation  of  so  well-known  an 
authority  on  this  subject  as  Dr.  Thorington.  Oculists  accustomed  to  casually  use 
retinoscopy  as  practised  in  the  old  way,  with  the  concave  mirror  or  with  the  ophthal- 
moscopic  mirror,  will  be  surprised  to  note  the  marked  evolution  of  the  modus  oper- 
andi  of  this  test  as  developed  by  Drs.  Jackson  and  Thorington.  With  perfected  in- 
struments and  strict  attention  to  arrangement  of  light,  distance,  and  other  details,  a 
surprising  degree  of  proficiency  and  accuracy  is  possible.  Any  one  pursuing  the 
modern  methods  of  retinoscopy  will  soon  be  convinced  of  its  superiority  over  all 
other  objective  tests,  and  every  worker  in  ophthalmology  realizes  the  necessity  of  at 
least  one  reliable  objective  method  of  refraction." 

From  "  The  New  Orleans  Medical  and  Surgical  Journal,"  New  Orleans,  La. 

"We  have  nothing  but  a  good  word  for  this  little  book.  It  seems  to  fulfil  well 
the  purpose  intended.  It  gives  a  brief,  clear  description  of  the  means  and  manner  of 
retinoscopy,  together  with  the  principles  or  natural  laws  upon  which  it  is  founded. 
The  author  has  done  well  in  selecting  the  method  he  thinks  best  and  simplest, and  has 
confined  himself  to  it,  so  that  the  student  will  have  no  difficulty  or  confusion  in  fol- 
lowing the  manual  step  by  step,  and  learning  to  put  in  practice  for  himself  what  is 
described  in  the  pages.  This  once  accomplished,  he  can  readily,  if  he  becomes  con- 
vinced of  its  usefulness,  acquire  the  variations  and  refinement  upon  this  mode  ot 
examination." 

From  "The  New  York  Medical  Journal,"  New  York. 

"  This  little  book  presents  as  simple  and  practical  a  description  of  the  shadow 
test  as  exists  in  our  language." 


Prom  "The  Scottish  Medical  and  Surgical  Journal,"  Edinburgh,  Scotland. 

"  Dr.  Thorington's  lucid  text  is  accompanied  by  twenty-four  good  illustrations, 
and  on  every  page  one  notes  that  careful  attention  has  been  paid  to  little  details  of 
manipulation  which  stamp  the  writer  as  a  practical  teacher." 

Prom  "The  Homeopathic  Eye,  Ear,  and  Throat  Journal,"  New  York. 

"  A  practical  and  useful  book.  This  is  one  of  the  most  concise  and  clearest  ex- 
planations of  this  subject  we  have  seen.  Retinoscopy  is  one  of  the  most  valuable  aids 
we  have  in  refractive  work." 

From  "  The  Denver  Medical  Times,"  Denver,  Col. 

"  His  directions  and  descriptions  are  exceptionally  clear  and  concise,  and  the 
little  book  he  has  written,  we  think,  will  be  helpful  to  every  physician  who  is  inter- 
ested in  the  fitting  of  glasses." 

Prom  "The  Chicago  Medical  Recorder,"  Chicago,  III. 

"  This  little  book  is  the  most  practical  and  complete  exposition  of  the  value  and 
application  of  the  shadow  test  in  determining  refractive  errors  with  which  we  have 
any  acquaintance.  The  illustrations,  directions,  advice,  and  general  information  in 
the  book  are  all  admirable." 

From  "The  Post-Qraduate,"  New  York. 

"  This  work  on  retinoscopy  is  divided  into  six  chapters  and  an  index.  As  stated 
in  the  preface,  it  is  an  abstract  of  the  author's  previous  writings  and  lectures  on 
retinoscopy,  delivered  at  the  Philadelphia  Polyclinic.  It  is  intended  for  college 
students  and  post-graduates,  yet  is  sufficiently  complete  for  the  use  of  the  ophthal- 
mologist. Retinoscopy  has  been  selected  as  the  name  of  the  test,  as  it  is  the  retina 
in  its  relative  position  to  the  refractive  media  which  is  studied.  Skiascopy  and  skia- 
graphy  are  therefore  regarded  as  misleading.  To  all  those  who  are  interested  in 
this  test  for  the  determination  of  refraction  we  commend  the  work." 

From  "The  Philadelphia  Polyclinic,"  Philadelphia. 

"  We  take  pleasure  in  commending  this  concise  statement  of  the  methods  to  be 
employed  in  the  routine  use  of  a  most  valuable  objective  means  of  determining  the 
errors  of  refraction.  The  student  is  told  in  simple  English  how  to  proceed  in  the 
examination." 

From  "The  Boston  Medical  and  Surgical  Journal,"  Boston,  Mass. 

"  This  little  manual  is  certainly  the  clearest  exposition  of  this  method  of  estimat- 
ing refraction  of  the  eye  that  has  yet  been  published.  The  methods  described  are  not 
so  complicated  as  those  taught  in  some  other  handbooks.  The  text  is  clear,  and  the 
illustrations  serve  the  purposes  for  which  they  are  designed  admirably.  Taken 
altogether,  it  is  the  most  practicable  handbook  on  retinoscopy  yet  published." 

From  "The   Journal   of   Ophthalmology,    Otology,   and    Laryngology,"  New- 
York. 

"  We  most  emphatically  recommend  this  little  book  to  the  beginner  in  the  study 
of  this  method  of  determining  refraction.  The  title  is  an  index  of  the  character  of  the 
text.  It  is  positive,  exact,  practical.  The  aim  of  the  author  has-been  to  present 
facts,  and  in  as  small  space  as  possible.  He  has  succeeded  absolutely.  The  average 
work  on  this  subject  is,  to  the  beginner,  somewhat  confusing,  from  the  amount  of 
theory  presented — theory  which  is  not  a'ways  clear  to  the  student.  This  has  been 
avoided  in  the  present  case.  Little,  if  any,  theory  is  included,  and  the  monograph  is 
a  series  of  categorical  statements — clear,  precise,  and  sufficient." 


#  *  *  The  price  of  this  book  (third  edition,  revised 
and  enlarged)  is  $J.OO  net,  upon  receipt  of  which  it  will 
be  sent  postpaid  to  any  address.  It  may  be  obtained  from 
the  publishers  or  through  any  bookseller  or  dealer  in 
opticians'  supplies. 


RETINOSCOPY 

(OR  SHADOW  TEST) 


DETERMINATION  OF  REFRACTION  AT  ONE  METER 
DISTANCE,  WITH  THE  PLANE  MIRROR 


JAMES  THORINGTON,  M.  D. 

ADJUNCT  PROFESSOR   OF   DISEASES  OF  THE  EYE  IN  THE  PHILADELPHIA  POLYCLINIC  AND 
COLLEGE  FOR  GRADUATES  IN  MEDICINE;   ASSISTANT  SURGEON  TO   WILL'S  EYE   HOS- 
PITAL; OPHTHALMOLOGIST  TO  THE  ELWYN  AND  VINELAND  TRAINING  SCHOOL  FOR 
FEEBLE-MINDED  CHILDREN;  OPHTHALMOLOGIST  TO  THE  M.  E.  ORPHANAGE; 
LECTURER  IN  THE  PHILADELPHIA  MANUAL  TRAINING  SCHOOLS,  1896-97. 
ON  THE  ANATOMY,  PHYSIOLOGY,  AND  CARE  OF  THE  EYES;  RESIDENT 
PHYSICIAN  AND  SURGEON  PANAMA  RAILROAD  CO.  AT  COLON 
(ASPINWALL),    ISTHMUS    OF    PANAMA,    1882-1889,    ETC. 


THIRD  EDITION,  REVISED  AND  ENLARGED 


FORTY-THREE    ILLUSTRATIONS 

TWELVE    OF    WHICH    ARE    COLORED 


PHILADELPHIA 

P.    BLAKISTON'S   SON    &   CO 

1012     WALNUT     STREET 
1899 


COPYRIGHT,  1899,  BY  JAMES  THORINGTON,  M.D. 


PRESS  or  WM.  F.  FELL  ft  Co.. 
I22O-24  SANSOM  ST.. 

PHILADELPHIA. 


BOOK   IS   AFFECTIONATELY   DEDICATED   TO   THE 
MEMORY  OF 

FELIX  A.  BETTELHEIM,  PH.D.,  M.D., 

MY    FRIEND    AND    ASSOCIATE    DURING    HIS    SIX    YEARS'     RESI- 
DENCE, AS   SURGEON  OF   THE  PANAMA  RAILROAD 
COMPANY,    AT    PANAMA. 


PREFACE  TO  THIRD   EDITION. 


The  first  edition  of  "  Retinoscopy  "  was  published 
in  March,  1897,  and  it  is  most  gratifying  to  the 
author  that  the  subject  continues  to  merit  sufficient 
attention  to  call  for  a  third  edition  in  less  than 
two  years.  Endeavoring  to  make  the  book  more 
worthy  of  the  favor  with  which  it  has  been  re- 
ceived and  for  a  clearer  understanding  of  the  sub- 
ject, some  few  changes  in  phraseology  have  been 
made  and  five  additional  illustrations  incorporated. 

120  S.  EIGHTEENTH  ST.,  PHILADELPHIA,  PA., 

February,  f8qg. 


PREFACE  TO  THE  SECOND  EDITION. 


The  first  edition  of  this  book  was  published  in 
March,  1897,  and  it  is  indeed  gratifying  to  the 
author  that  the  work  has  found  such  favor  as  to 
call  for  a  second  in  so  short  a  time. 

To  make  this  edition  more  lucid  than  the  first, 
the  writer  has  carefully  reviewed  the  original  text 
and  made  some  changes  in  the  phraseology,  and  at 
the  same  time  has  added  many  new  illustrations, 
twelve  of  which  are  in  colors. 

A  description  and  drawings  of  three  lenses,  sug- 
gested by  the  author  for  the  study  of  the  scissor 
movement,  conic  cornea,  and  spheric  aberration  on 
the  schematic  eye,  have  also  been  inserted. 

1 20  S.  EIGHTEENTH  ST.,  PHILADELPHIA,  PA., 
February,    1898. 


PREFACE  TO  THE  FIRST  EDITION. 


At  the  earnest  solicitation  of  many  students  and 
friends,  this  book  is  presented  as  an  abstract  of  the 
author's  previous  writings  and  lectures  on  Retinos- 
copy,  delivered  during  the  winter  course  on  Oph- 
thalmology, at  the  Philadelphia  Polyclinic. 

In  presenting  a  manual  of  this  kind  the  writer 
does  not  presume  to  detract  from  the  writings  or 
teachings  of  others,  or  the  excellent  work  on  Skia- 
scopy,  by  his  friend  and  colleague.  Dr.  E.  Jackson  ; 
but  wishes  to  elucidate  in  as  concise  a  manner  and 
few  words  as  possible  the  method  of  applying 
retinoscopy,  which  has  given  most  satisfaction  at 
his  hands. 

While  intended  for  college  students  and  post- 
graduates, yet  there  is  ample  material  given  where- 
by the  ophthalmologist  at  a  distance  may  acquire  a 
working  knowledge  of  the  method,  by  study  and 
practice  in  his  own  office. 


xiv  PREFACE   TO   THE    FIRST   EDITION. 

For  three  reasons  Retinoscopy,  in  preference  to 
Skiascopy,  has  been  chosen  as  the  title : 

First,  that  it  may  not  be  confounded  with  Skia- 
graphy. 

Second,  that  it  is  the  name  by  which  the  test  is 
universally  known  ;  and — 

Third,  that  it  is  the  retina  in  its  relative  position 
to  the  dioptric  media  which  we  study. 

120  S.  EIGHTEENTH  ST.,  PHILADELPHIA,  PA., 
March , 


CONTENTS. 


CHAPTER  I. 

PAGE 

DEFINITION. — NAMES. — PRINCIPLE  AND  VALUE  OF  RETINOSCOPY  — 

SUGGESTIONS  TO  THE  BEGINNER, '9-23 

CHAPTER  II. 

RETINOSCOPE. — LIGHT.— LIGHT-SCREEN.— DARK  ROOM.— SOURCE  OF 

LIGHT  AND  POSITION  OF  MIRROR. — OBSERVER  AND  PATIENT,  .  24-30 

CHAPTER  III. 

DISTANCE  OF  SURGEON  FROM  PATIENT. — ARRANGEMENT  OF  PATIENT, 
LIGHT,  AND  OBSERVER. — REFLECTION-  FROM  MIRROR. — How 
TO  USE  THE  MIRROR. — WHAT  THE  OBSERVER  SEES. — RETINAL 
ILLUMINATION. — SHADOW. — WHERE  TO  LOOK  AND  WHAT  TO 
LOOK  FOR, 3!~39 

CHAPTER  IV. 

POINT  OF  REVERSAL. — To  FIND  THE  POINT  OF  REVERSAL. — WHAT 
TO  AVOID. — DIRECTION  OF  MOVEMENT  OF  RETINAL  ILLUMINA- 
TION.—RATE  OF  MOVEMENT  AND  FORM  OF  ILLUMINATION. — 
RULES  FOR  LENSES. — MOVEMENT  OF  MIRROR  AND  APPARATUS,  40-50 

CHAPTER  V. 

RETINOSCOPY  IN  EMMETROPIA  AND  THE  VARIOUS  FORMS  OF  REGU- 
LAR AMETROPIA. — AXONOMETER, 51-67 

CHAPTER  VI. 

RETINOSCOPY  IN  THE  VARIOUS  FORMS  OF  IRREGULAR  AMETROPIA. — 
RETINOSCOPY  WITHOUT  A  CYCLOPLEGIC. — THE  CONCAVE  MIR- 
ROR.— DESCRIPTION  OF  THE  AUTHOR'S  SCHEMATIC  EYE  AND 
LIGHT-SCREEN.  —  LENSES  FOR  THE  STUDY  OF  THE  SCISSOR 
MOVEMENT,  CONIC  CORNEA,  AND  SPHERIC  ABERRATION,  .  .  .  68-83 

INDEX, 85-86 


LIST  OF   ILLUSTRATIONS. 


FIG.  PAGE 

1 .  Schematic  Eye  for  Studying  Retinoscopy, 22 

2.  Retinoscope, 25 

3.  Light-screen,  or  Cover  Chimney, 26 

4.  New  Light-screen, 27 

5.  Showing  Distance  from  Patient's  Eyes  and  the  Equivalent  in  Diop- 

ters,        32 

6.  Arrangement  of  Patient,  Light,  and  Observer, 33 

7.  Light  over  Patient's  Head,  and  the  Observer  with   Mirror  at  One 

Meter  Distance, 34 

8.  Folding  Mirror, 35 

9.  Folding  Mirror  with  Illumination 35 

10.  Illumination  in  an  Emmetropic  Eye, 38 

11.  Illumination  and  Shadow  in  an  Emmetropic  Eye, 38 

12.  Illumination  with  Straight  Edge, 46 

13.  Illumination  with  Crescent  Edge, 46 

14.'  Wiirdemann's  Disc, 47 

15.  Jennings'  Skiascopic  Disc, 48 

16.  Gray  Reflex  as  seen  in  High  Hyperopia, 51 

17.  Gray  Reflex,  Crescent  Edge,  and  Shadow  in  High  Hyperopia,  ...  51 

1 8.  Hyperopia, 52 

19.  Refracted  Hyperopia, 53 

20.  Emmetropia, 54 

21.  Refraction  of  Macular  Region,      55 

22.  Myopia, 56 

23.  Refracted  Myopia, 57 

24.  Method  of  Writing  a  Formula, 60 

25.  Band  of  Light  in  Astigmatism, 61 

26.  Band  of  Light  and  Shadow, 61 

27.  Band  of  Light,  Axis  90°,      62 

28.  Band  of  Light  Showing  Half  a  Diopter  of  Astigmatism 63 

29.  Axonometer, 66 

30.  Axonometer  in  Position, 66 

31.  32.  Irregular  Lenticular  Astigmatism, 69 

34.  Two  Bands  of  Light, 70 

33.   Light  Areas  with  Dark  Interspace,      .    .    • 7 1 

35.  Light  Areas  Brought  Together, 71 

2  xvii 


LIST  OF  ILLUSTRATIONS. 


36.  Tilting  of  Lens,      ......................  7* 

37.  Scissor  Movement  in  Refracted  Aphakia,   ...  -73 

38.  Illumination  Seen  in  Conic  Cornea,    ..............  75 

39.  Positive  Aberration,  .............                             •    •  7& 

40.  Negative  Aberration,     ....................  7° 

41.  Lens  for  the  Study  of  the  Scissor  Movement,     .    .  8l 

42.  Lens  for  the  Study  of  Conic  Cornea,  .                                               .    .  81 

43.  Lens  for  the  Study  of  Spheric  Aberration,  81 


RETINOSCOPY. 


CHAPTER  I. 

DEFINITION.— NAMES.— PRINCIPLE  AND  VALUE  OF 

RETINOSCOPY.— SUGGESTIONS  TO  THE 

BEGINNER. 

Definition. — Retinoscopy  (see  preface  to  first 
edition)  may  be  defined  as  the  method  of  estimating 
the  refraction  of  an  eye  by  reflecting  into  it  rays  of 
light  from  a  plane  or  concave  mirror,  and  observing 
the  movement  which  the  retinal  illumination  makes 
by  rotating  the  mirror. 

Names. — Dioptroscopy,  fundus-reflex  test,*  kera- 
toscopy,  fantoscopy,  pupilloscopy,  retinophotoscopy, 
retinoskiascopy,  skiascopy,  umbrascopy,  koroscopy, 
etc.,  are  some  of  the  other  names  given  to  this 
method  of  refraction,  and  their  number  and  greater 
or  less  inappropriateness  have  had  much  to  do,  no 
doubt,  with  keeping  retinoscopy  in  the  background 
of  ophthalmology  instead  of  giving  it  the  promi- 
nence which  it  more  justly  deserved  and  now  re- 
ceives. 

*  Suggested  by  Dr.  C.  A.  Oliver. 
19 


20  KKTINOSCOPY. 

f 

The  principle  of  retinoscopy  is  the  finding  of 
the  point  of  reversal  (the  far-point  of  a  myopic  eye), 
and  to  do  this,  if  an  eye  is  not  already  sufficiently 
myopic,  it  will  be  necessary  to  place  in  front  of  it 
such  a  lens,  or  series  of  lenses,  as  will  bring  the 
emergent  rays  of  light  to  a  focus  at  a  certain  definite 
distance  (see  Point  of  Reversal,  chap.  iv). 

Value  of  Retinoscopy. — Those  who  would 
criticize  retinoscopy  because  "we  see  nothing  and 
think  nothing  of  the  condition  of  the  fundus,"  base 
their  criticism  apparently  on  the  name,  retinoscopy, 
rather  than  from  any  great  amount  of  practical  ex- 
perience with  the  method.  While  admitting  that  the 
ophthalmoscope  in  front  of  a  well-trained  eye  can 
often  make  a  close  refractive  estimate,  yet  only  to 
the  few  does  such  skill  obtain,  and  even  then  there 
is  that  uncertainty  which  does  not  attach  itself  to  the 
retinoscope  in  competent  hands.  The  ophthalmolo- 
gist who  knows  how  to  use  the  mirror  accurately 
has  the  advantage  of  his  confreres  who  are  ignorant 
of  the  test ;  it  gives  him  a  position  decidedly  inde- 
pendent of  his  patient,  and  puts  him  above  the 
common  level  of  the  traveling  "  Great  Doctor  Eye  " 
and  "refracting  optician,"  who  are  tied  to  the  trial- 
lenses  and  the  patient's  uncertain  answers.  Further- 
more, when  it  is  remembered  that  from  fifty  to  eighty 
per  cent,  of  the  patients  consulting  the  ophthalmolo- 
gist do  so  for  an  error  of  refraction,  it  is  well  that 
he  be  most  capable  in  this  important  branch  of  the 
subject. 

The  wonderful  advantage  ot  retinoscopy  over 
other  methods  needs  no  argument  to  uphold  it;  the 


VALUE   OF   RETINOSCOPY.  21 

rapidly  increasing  number  of  retinoscopists  testify 
to  its  merits. 

The  writer,  from  his  constant  use  of  the  mirror, 
would  suggest  the  following  axiom  :  That,  with  an 
eye  otherwise  normal  except  for  its  refractive  error, 
and  being  under  the  influence  of  a  reliable  cycloplegic, 
there  is  no  more  accurate  objective  method  of  obtaining 
its  exact  correction  than  by  retinoscopy. 

Retinoscopy  gives  the  following  advantages  : 

The  character  of  the  refraction  is  quickly  diag- 
nosed. 

The  exact  refraction  is  obtained  without  question- 
ing the  patient. 

Little  time  is  required  to  make  the  test. 

No  expensive  apparatus  is  necessarily  required. 

Its  great  value  can  never  be  overestimated  in 
nystagmus,  young  children,  amblyopia,  aphakia,  illit- 
erates, and  the  feeble-minded. 

From  what  has  just  been  written,  it  must  not  be 
understood  that  the  patient's  glasses  are  ordered 
immediately  from  the  result  obtained  by  retinos- 
copy ;  for,  on  the  contrary,  all  retinoscopic  work, 
like  ophthalmometry  in  general,  should,  when  possi- 
ble, be  confirmed  at  the  trial-case. 

It  is  only  in  the  feeble-minded,  in  young  children, 
and  in  cases  of  amblyopia  that  glasses  are  ordered 
direct  from  the  result  obtained  in  the  dark  room. 

The  subjective  method  of  placing  lenses  before 
the  patient's  eyes  and  letting  him  decide  by  asking 
"is  this  better?"  or  "is  this  worse?"  only  too  often 
fatigues  the  examiner  and  worries  the  patient,  giving 
him  or  her  a  dread  or  fear  of  inaccuracy  that  does 


22 


RETINOSCOPY. 


not  satisfy  the  surgeon  or  tend  to  inspire  the  patient. 
Whereas,  when  the  neutralizing  lenses  found  by 
retinoscopy  are  placed  before  the  patient's  eyes  and 
he  reads  f  or  f$  or  more,  it  is  easy,  if  there  is  any 
doubt,  to  hold  up  a  plus  and  a  minus  quarter  diopter 


FIG.  i.— THE  AUTHOR'S  SCHEMATIC  EYE  FOR  STUDYING   RETINOSCOPY. 
(For  description,  see  chap,  vi.) 

glass  respectively  in  front  of  this  correction,  and  let 
the  patient  tell  at  once  if  either  glass  improves  or 
diminishes  the  vision. 

The  writer  is  not  condemning  the  subjective  or 
other  methods  of  refraction,  or  trying  to  extol  too 


SUGGESTIONS   TO   THE   BEGINNER.  23 

highly  the  shadow  test,  yet  he  would  remind  those 
who  try  retinoscopy,  fail,  and  then  ridicule  it,  that 
the  fault  with  them  is  back  and  not  in  front  of  the 
mirror. 

Suggestions  to  the  Beginner. — To  obtain  profi- 
ciency in  retinoscopy  there  is  much  to  be  understood. 
Careful  attention  to  details  must  be  given,  and  not  a 
little  patience  possessed,  as  it  is  not  a  method  that  is 
acquired  in  a  day,  and  it  is  only  after  weeks  of  con- 
stant application  that  accuracy  is  acquired.  There- 
fore the  beginner  is  strongly  advised  to  learn  the 
major  points  from  one  of  the  many  schematic  eyes 
in  the  market  before  attempting  the  human  eye.  At 
the  same  time  he  should  be  perfectly  familiar  with 
the  laws  of  refraction  and  dioptrics,  as  an  understand- 
ing of  conjugate  foci  is  really  the  underlying  prin- 
ciple of  the  method — i.  e.,  a  point  on  the  retina  being 
one  focus  and  the  myopic  or  artifically-made  far- 
point  the  other  focus. 

What  is  meant  by  major  points  applies  more  par- 
ticularly to  the  study  of  the  retinal  illumination,  its 
direction  and  apparent  rate  of  movement,  also  its 
form,  the  distance  between  the  observer  and  the 
patient,  how  to  handle  the  mirror,  etc.,  all  of  which 
are  referred  to  under  their  special  headings. 


CHAPTER  II. 

RETINOSCOPE.-LIGHT.-L1GHT-SCREEN.-DAPK    ROOM. 

-SOURCE  OF  LIGHT  AND  POSITION  OF  MIRROR.- 

OBSERVER  AND  PATIENT. 

The  Retinoscope,  or  Mirror. — Two  forms  of 
the  plane  mirror  are  in  use — the  one  large,  four  centi- 
meters in  diameter,  with  a  four-  or  five-millimeter 
sight-hole  often  cut  through  the  glass  ;  and  the  other 
small,  two  centimeters  in  diameter,  on  a  four-centi- 
meter metal  disc,  with  sight-hole  two  millimeters  in 
diameter,  not  cut  through  the  glass,  the  quicksilver  or 
plating  alone  being  removed.  By  thus  leaving  the 
glass  at  the  sight-hole,  additional  reflecting  surface 
is  obtained  at  this  point,  which  assists  materially  in 
exact  work,  as  it  diminishes  the  dark  central  shadow 
that  shows  so  conspicuously  at  times,  and  particularly 
when  the  sight-hole  is  cut  through  the  glass.  The  small 
mirror  has  an  advantage  over  the  large  by  reducing 
the  area  of  reflected  light,  as  only  a  one-centimeter 
area  on  each  side  of  the  sight-hole  is  of  particular  use. 
The  small  plane  mirror  *  is  the  one  recommended, 
and  is  made  with  either  a  straight  or  folding  handle  ; 
the  latter  is  for  the  purpose  of  protecting  the  mirror 
when  carried  in  the  pocket.  The  purpose  of  the 

* Philadelphia  Pofyclinic,  November,  1893.  Another  form  is 
described  by  Dr.  E.  Jackson,  American  Jmtrnal  of  Ophthal- 
n.ology,  April,  1896. 

24 


THE   LIGHT.  25 

metal  disc  on  which  the  small  mirror  is  secured  is  to 
keep  the  light  out  of  the  observer's  eye,  and  enable 
him  to  rest  the  instrument  against  the  brow  and  side 
of  the  nose  ;  but  if  its  size  should  appear  small,  the 
observer  can  easily  have  a  larger  one  made  to  suit 
his  convenience.  The  plating  or  silvering  on  the 
mirror  should  be  of  the  best,  and  free  from  any 
flaws  or  imperfections,  for  on  its  quality  depends,  in 
part,  the  good  reflecting  power  of  the  mirror,  which 
is  very  important. 


FIG.  2. — THE  AUTHOR'S  RETINOSCOPE.* 

The  central  shadow  just  referred  to  as  the  result 
of  the  sight-hole  had  best  be  seen  by  the  beginner 
by  reflecting  the  light  from  the  mirror  onto  a  white 
surface,  before  he  begins  any  study,  as  this  dark 
area  may  annoy  him  later  if  he  does  not  understand 
its  origin. 

The  Light. — This  should  be  steady,  clear,  and 
white.  The  Welsbach  possesses  all  these  qualities, 
but  unfortunately  its  delicate  mantle  will  not  stand 

*  See  foot-note  on  preceding  page. 


26 


RETINOSCOPY. 


much  jarring,  and  is  easily  broken  in  consequence, 
causing  much  loss  of  time  and  annoyance.  The 
electric  light  with  a  twisted  carbon  and  ground-glass 
covering  with  a  round  center  of  clear  glass  is  grow- 
ing quite  popular.  For  constant  service,  however, 
the  Argand  burner  is  decidedly  the  best,  when  the 
asbestos  light-screen  is  used  to  intercept  the  heat. 
Whatever  light  is  employed,  it  is 
well  to  have  it  on  an  extension 
bracket,  so  that  the  observer  may 
move  it  toward  or  away  from  the 
patient,  as  necessary. 

The  light-screen,  or  cover 
chimney,  is  made  of  one-eighth 
inch  asbestos,  and  of  sufficient 
size  (six  centimeters  in  diameter 
by  twenty-one  in  height)  to  fit 
over  the  glass  chimney  of  the 
Argand  burner. 

Attached  to  the  screen  are  two 
superimposed  revolving  discs  that 
furnish  four  round  openings,  re- 
spectively five,  ten,  twenty,  and 
thirty  millimeters,  any  one  ot 
which  may  be  turned  into  place 
as  occasion  may  require.  Care  should  be  taken  that 
the  opening  used  is  placed  opposite  to  the  brightest, 
and  never  opposite  to  the  edge  or  the  blue  part  of  the 
flame.  Formerly  these  screens  were  made  of  sheet- 
iron,  but  the  asbestos  has  been  found  preferable,  as 
it  does  not  radiate  the  heat  to  the  same  extent  as  the 
iron.  The  purpose  of  the  light-screen  is  to  cover  all 


FIG.  3. — THE  AUTHOR'S 
LIGHT-SCREEN,  OR 
COVER  CHIMNEY. 

(far  a  further  descrip- 
tion, see  chap,  vi.) 


DARK   ROOM. 


27 


of  the  flame  except  the  portion  which  presents  at 
the  opening  in  the  disc. 

Ten-millimeter  Opening. — This  will  be  used 
in  most  all  retinoscopic  work  by  the  beginner. 

Five-millimeter  Opening. — This  is  used  to  the 
best  advantage  and  with  no  small  amount  of  satis- 
faction by  the  expert  when  working  close  to  the 
point  of  reversal.  Figure  4  shows 
the  author's  new  light-screen, 
which  was  described  on  page 
1378  in  the  "Journal  of  the 
American  Association,"  Decem- 
ber 3,  1898.  This  is  a  more 
convenient  screen  for  retinos- 
copy  than  the  one  shown  in 
figure  3.  It  is  made  by  attach- 
ing an  iris  diaphragm  to  an 
asbestos  chimney.  The  amount 
of  light  passing  through  the  dia- 
phragm is  easily  controlled  by 
an  ivory-tipped  lever  at  the  left- 
hand  side  ;  and  an  index  on  the 
periphery  records  the  diameter 
of  the  opening  in  use,  from  one 
to  thirty  millimeters. 

The  room  must  be  darkened, — and  the  darker 
the  better, — all  sources  of  light  to  be  excluded  ex- 
cept the  one  in  use.  It  must  not  be  supposed  from 
this  that  the  room  must  have  its  walls  and  ceiling 
blackened  ;  on  the  contrary,  if  the  shades  are  drawn, 
the  room  will  be  sufficiently  dark,  though  of  course 
a  perfectly  black  room  would  be  best,  as  giving  a 


FIG.  4. — THE  AUTHOR'S 
NEW  LIGHT-SCREEN. 


28  RETINOSCOPY. 

greater  contrast  to  the  condition  to  be  studied.  The 
exclusion  of  other  lights,  or  beams  of  light,  must  be 
insisted  upon,  as  the  principal  use  of  the  darkened 
room  is  to  keep  all  light  except  the  light  in  use  out 
of  the  eye  to  be  examined,  and  also  not  to  have 
other  lights  reflected  from  the  mirror. 

As  the  method  of  using  the  concave  mirror  with 
source  of  light  (twenty  or  thirty  mm.  opening  in 
screen)  beyond  its  principal  focus  (usually  over  and 
beyond  the  patient's  head)  has  been  superseded  by 
the  simpler  and  easier  method  of  using  the  small  plane 
mirror  with  source  of  light  (one-half  or  one  cm.  open- 
ing in  light-screen)  brought  as  close  to  the  mirror  as 
possible,  the  description  of  retinoscopy  which  follows 
will  refer  to  the  latter. 

The  Source  of  Light  and  Position  of  the 
Mirror. — The  rays  of  light  coming  out  of  the  round 
opening  in  the  light-screen  should  be  five  or  six 
inches  to  the  left  and  front  of  the  observer,  so  that 
they  may  pass  in  front  of  the  left  eye  and  fall  upon 
the  mirror  held  before  the  right,  thus  leaving  the 
observer's  left  eye  in  comparative  darkness ;  or  the 
observer  may  use  the  mirror  before  the  left  eye  in 
case  he  is  left-handed  and  has  the  light  to  his  right. 
It  is  always  best  for  the  observer  to  keep  both  eyes 
wide  open  and  to  avoid  having  any  light  fall  into 
the  unused  eye,  which  would  cause  him  much  annoy- 
ance. Some  observers  hold  the  mirror  before  the 
eye  next  to  the  screen,  but  this  is  not  recommended, 
for  the  reasons  just  mentioned. 

The  observer  need  not  make  any  note  of  his  ac- 
commodation, as  in  using  the  ophthalmoscope,  but, 


THE  SOURCE  OF  LIGHT  AND  POSITION  OF  MIRROR.      29 

as  he  requires  very  acute  vision,  he  should  wear  any 
necessary  correcting  glasses.  Any  observer  whose 
vision  does  not  approximate  f  will  not  get  much  satis- 
faction from  retinoscopy. 

He  should  take  his  seat  facing  the  patient,  and,  as 
the  strength  of  the  reflected  light  rapidly  weakens  as 
the  distance  between  the  mirror  and  the  light-screen 
is  increased,  he  should  have  the  light-screen  close  to 
his  face  (not  less  than  six  inches)  if  he  wishes  to  get 
the  fullest  possible  strength  of  light  on  the  mirror. 

As  the  light  appears  just  as  far  back  in  the  mirror 
as  it  is  in  front  of  it,  then  the  nearer  these  two 
objects  are  brought  together,  the  more  nearly  do 
they  become  as  one.  When  working  close  to  the 
point  of  reversal,  more  exact  work  will  be  accom- 
plished if  this  distance  between  the  light  and  mirror 
is  very  short.  The  nearer  together  the  light  and 
mirror,  the  brighter  the  retinal  illumination,  and 
greater  contrast,  or  sharper  cut  edge  between  illu- 
mination and  surrounding  shadow.  The  further 
the  light  from  the  mirror,  the  smaller  the  retinal 
illumination,  and  there  will  appear,  under  certain 
conditions,  a  very  conspicuous  central  shadow  as 
the  result  of  the  sight-hole  in  the  mirror — two  very 
serious  objections. 

The  patient  must  have  his  accommodation  thor- 
oughly relaxed  with  a  reliable  cycloplegic,  and  should 
be  seated  comfortably,  one  meter  distant,  in  front 
of  the  observer,  with  his  vision  steadily  fixed  on  the 
observer's  forehead,  just  above  the  mirror.  Or,  what 
is  even  better,  the  patient  may  concentrate  his  vision 
on  the  edge  of  the  metal  disc  ot  the  mirror,  but 


30  RETINOSCOPY. 

never  directly  into  the  mirror,  as  that  would  soon 
irritate  and  compel  him  to  close  his  eye. 

In  this  way  the  patient  avoids  the  strain  of  look- 
ing into  the  bright  reflected  light,  and  at  the  same 
time  the  macular  region  is  refracted  (see  Fig.  21).  It 
is  customary  to  cover  the  patient's  other  eye  while 
its  fellow  is  being  refracted ;  for  obvious  reasons 
this  is  specially  important  in  cases  of  "squint." 


CHAPTER  III. 

DISTANCE  OF  SURGEON  FROM  PATIENT.-ARRANGE- 
MENT  OF  PATIENT,  LIGHT,  AND  OBSERVER.-RE- 
FLECTION  FROM  MIRROR. -HOW  TO  USE  THE 
MIRROR. -WHAT  THE  OBSERVER  SEES.-  RETINAL 
ILLUMINATION.— SHADOW.— WHERE  TO  LOOK  AND 
WHAT  TO  LOOK  FOR. 

Distance  of  Surgeon  from  Patient. — There  is 
no  fixed  rule  for  this,  and  each  surgeon  may  select 
his  own  distance.  It  might  be  well  for  the  beginner 
to  try  different  distances  and  then  choose  for  himself. 
The  writer  prefers  a  one  meter  distance,  and  with 
few  exceptions  adheres  to  it.  Some  prefer  six 
meters,  others  two  meters,  etc.  The  distance  of  one 
meter  has  important  advantages :  There  is  no  get- 
ting up  or  down  to  place  lenses  in  front  of  the 
patient's  eye,  as  the  patient  or  surgeon,  or  both,  may 
lean  forward  for  this  purpose,  if  necessary.  Another 
advantage  is  that  at  one  meter  distance  there  is  a 
uniform  allowance  of  one  diopter  in  the  estimate, 
which  will  be  explained  more  fully  under  Rules  for 
Retinoscopy  at  One  Meter.  To  get  the  patient's 
eye  and  the  observer's  forehead  just  one  meter 
apart,  the  distance  may  be  marked  off  on  the  wall  of 
the  dark  room  on  the  side  where  the  light  is  secured 
(see  Fig.  6),  or  a  meter  stick  for  the  purpose  may  be 
held  in  the  hand  of  the  observer  or  his  assistant. 

The  method  of  obtaining  the  point  of  reversal 

31 


fcETINOSCOPY. 


050 

0 

062 

II 

075 

I 

087 

40 

I.P 

» 

Uu 

1.5 

I2SD 

>6?5 

1501 

KJ 

1.75  D 

20 

Z.1 

1750 

i*s» 

U.7S 

rs« 

I4J 
O 

tn 
aj 

fs 

3501 

10 

4J> 

873 

jilt 

4  

6S7— 

5D 
550  » 

6       ^ 

=*aB7J>7M" 

W 


at  points  other  than  the  regula- 
tion one  meter  requires  such  an 
amount  of  extra  measuring  and 
computing  that  it  does  not  meet 
with  the  general  favor  and  satis- 
faction accorded  to  that  found  by 
producing  an  artificial  myopia  of 
one  diopter.  This  can  best  be 
explained  by  reference  to  figure 
5,  where,  if  the  observer  is  at 
one  diopter,  and  the  neutralizing 
lenses  in  front  of  the  patient's 
eye  focus  the  emergent  rays  at 
about  that  distance,  he  may  have 
the  liberty  of  moving  forward  five 
inches  or  backward  five  inches  (a 
play  of  ten  inches)  in  looking  for 
the  point  of  reversal,  and  not 
make  a  possible  error  in  his  re- 
sult of  more  than  twelve  one- 
hundredths  (0.12)  of  a  diopter; 
whereas  if  he  were  working 
closer  than  this,  he  would  likely 
make  an  error  of  0.5  D.,  or  even 
more,  if  he  were  not  extremely 
careful  in  measuring  the  distance 
at  which  he  found  the  reversal 
point. 

Arrangement  of  Patient, 
Light,  and  Observer. — This 
has  already  been  described  in 
great  part,  but  reference  to  the 


ARRANGEMENT  OF  PATIENT,  LIGHT,  AND  OBSERVER.     33 

accompanying  sketch  may  give  the  student  a  more 
exact  appreciation  of  the  arrangement  than  any 
lengthy  description  could  do. 

For  convenience  of  the  beginner  in  using  the 
mirror,  it  is  best,  as  here  shown,  to  keep  the  sur- 
geon's eye,  the  light,  and  the  patient's  eye  on  a 
horizontal  line,  and  to  accomplish  this  in  children 


FIG.  6. — ARRANGEMENT  OF  PATIENT,  LIGHT,  AND  OBSERVER. 


they  will  either  have  to  stand,  sit  on  a  high  stool, 
or  on  the  parent's  lap.  The  beginner  will  find  it 
sufficiently  difficult  at  first  to  keep  the  light  on  the 
patient's  eye  with  the  mirror  held  perpendicularly, 
without  inclining  it  up  or  down,  as  he  would  have  to 
do  if  the  arrangement  suggested  is  not  carried  out. 
Placing  the  light  to  one  side  of  the  patient's  head, 
or  above  it,  and  the  observer  seated  at  one  meter 


34  RETINOSCOPY. 

distance  from  the  patient,  is  a  convenient  way  of 
working  retinoscopy.  It  has  two  advantages :  the 
observer  avoids  the  heat  of  the  flame,  and  at  the 
same  time  does  not  have  to  move  the  light.  But 
the  writer  is  not  partial  to  this  mode  of  procedure, 
for  various  reasons  of  precision,  explained  in  the 
text.  Figure  7  shows  the  observer's  eye,  one 
meter  from  the  patient's  eye,  and  the  light  above. 


I  METER 


¥\G.  7.— LIGHT  OVER  PATIENT'S  HEAD,  AND  THE  OBSERVER  WITH 
MIRROR  AT  ONE  METER  DISTANCE. 


Reflection  from  the  Mirror. — The  rays  of  light 
coming  from  the  round  opening  in  the  screen  to  the 
plane  mirror  are  reflected  divergently,  as  if  they 
came  from  the  opening  in  the  screen  situated  just  as 
far  back  in  the  mirror  as  they  originally  started  from 
in  front  (see  Figs.  18,  20,  and  22),  and  the  patient, 
looking  into  the  mirror,  sees  a  round,  bright  spot  of 
light,  just  as  large  as  the  opening  in  the  screen. 

How  to  Use  the  Mirror. — It  should  be  held 
firmly  before  the  right  eye  so  that  the  sight-hole  is 


HOW   TO   USE   THE   MIRROR. 


35 


opposite  to  the  observer's  pupil ;  and  that  it  may  be 
steady,  the  second  phalanx  of  the  thumb  should  rest 
on  the  cheek  just  below  the  eye,  the  edge  of  the 
metal  disc  even  touching  the  side  of  the  nose  if  the 
observer's  interpupillary  distance  is  not  too  great. 
Thus  held  in  position,  its  movements  should  be  very 


FIG.  8.  FIG.  9. 

AUTHOR'S  MIRROR  WJTH  FOLDING  HANDLE. 

FIG.  8. — Showing  central  light  C,  on  small  mirror  B.  This  is  the  light  the 
patient  sees  when  looking  into  the  mirror,  and  corresponds  in  size  to  the 
one-centimeter  opening  in  screen.  D  is  the  folding  cap  handle  to  pro- 
tect B  when  not  in  use.  A  is  the  metal  disc. 

FIG.  9. — Shows  the  light  moved  to  one  side  as  a  result  of  tilting  the  mirror. 


limited,  though  they  may  be  slow  or  quick,  but  never, 
at  any  time,  should  it  be  tilted  more  than  one,  two,  or 
even  three  millimeters  ;  for  if  inclined  more  than  this, 
the  light  is  lost  from  the  patient's  eye.  If  the  light, 
the  patient's,  and  the  observer's  eyes  are  on  a 


36  RETINOSCOPY. 

horizontal  line,  then  to  find  the  patient's  eye  with  the 
reflected  light  all  the  observer  has  to  do  is  to  reflect 
the  light  back  into  the  light-screen,  and  by  rotating 
the  mirror  to  his  right,  carry  the  reflected  light 
around  on  the  same  line  until  the  patient's  eye  is 
reached.  This  may  seem  like  a  superabundance  of 
instruction,  but  the  finding  of  the  patient's  eye,  which 
appears  so  easy,  is  an  immense  stumbling-block,  at 
the  beginning,  to  most  students.  Another  way  to 
find  the  eye  is  for  the  observer  to  hold  his  left  hand 
up  between  his  and  the  patient's  eye  and  reflect  the 
light  on  to  it,  and  when  this  is  done  to  drop  his  hand 
and  let  the  light  pass  into  the  observed  eye.  Hav- 
ing succeeded  in  finding  the  patient's  eye,  the 
observer,  if  he  is  not  very  careful  in  his  limited 
movements  of  the  mirror  and  himself,  will  turn  the 
light  from  the  eye  almost  before  he  knows  it,  and 
so  be  compelled  to  start  and  find  it  again ;  this 
causes  much  loss  of  time.  A  little  practice  on  the 
schematic  eye  will  assist  the  beginner  wonderfully 
and  give  him  courage,  for  if  he  hastens  to  the  human 
eye,  and  then  has  to  stop  every  minute  or  so  to  try 
and  get  the  light  on  the  eye,  he  soon  becomes 
discouraged  and  shows  his  want  of  experience  to 
the  patient. 

What  the  observer  sees ;  or  the  general  ap- 
pearance of  the  reflection  from  the  eye. — With  the 
mirror  held  still  before  his  eye,  and  close  up  to  the 
bright  light  coming  from  the  ten-millimeter  opening 
in  the  light-screen,  the  observer  will  obtain  a  reflec- 
tion from  the  patient's  eye  which  varies  in  different 
patients,  and  is  subject  to  certain  changes  in  the 


WHAT   THE   OBSERVER    SEES.  37 

same  patient  as  the  refraction  is  altered  by  correct- 
ing lenses,  or  it  may  be  changed  by  the  turning  of 
the  patient's  eye,  or  lengthening  the  distance  be- 
tween the  mirror  and  the  light,  or  increasing  or 
diminishing  the  strength  of  the  light,  or  increasing 
the  distance  between  the  observer  and  the  patient. 
The  reflection  from  the  eye  of  the  albino  or  blond  is 
much  brighter  than  from  the  brunette  or  mulatto,  in 
whom  it  is  not  so  bright,  even  dim.  This  character 
of  the  reflex  is  controlled,  of  course,  in  great  part 
by  the  amount  of  pigment  in  the  eye  ground  ;  how- 
ever, in  most  instances  there  is  more  or  less  of  an 
orange-red  color  to  the  reflex,  and  this  is  especially 
so  as  the  point  of  reversal  is  approached.  Cases  of 
high  errors  of  refraction  give  a  dull  reflex  (see  Fig. 
1 6)  as  compared  to  low  errors,  where  the  reflex  is 
usually  very  bright  (see  Fig.  10).  Should  the  media 
be  irregular  or  not  perfectly  clear,  the  reflex  is  altered 
accordingly  ;  this  will  be  referred  to  under  the  head 
of  Irregular  Astigmatism.  The  observer  will  also 
notice  on  the  cornea  and  lens  bright  pin-point 
catoptric  images,  and  at  the  inner  edge  of  the  iris, 
in  many  eyes,  a  very  bright  ring  of  light  (see  Fig.  10) 
about  one  millimeter  in  width,  which  is  due  to  the 
very  strong  peripheral  refraction  ;  and  as  the  eye  is 
being  refracted  and  the  point  of  reversal  approached, 
this  peripheral  ring  may  develop  into  a  broader  ring 
of  aberration  rays,  which  at  times  will  be  annoying. 
This  will  be  referred  to  under  Spheric  Aberration, 
chapter  vi. 

Retinal  Illumination. — By  holding  a  strong  con- 
vex lens  closer  to  or  further  from  a  plane  surface 


38  RETINOSCOPY. 

than  its  principal  focus,  or  at  the  distance  of  its 
principal  focus,  and  letting  the  sun's  rays  pass 
through  it,  there  will  be  seen  on  the  plane  surface 
a  round  area  of  light ;  it  is  this  light  area  which  cor- 
responds to  the  illumination  on  the  retina,  seen  in 
retinoscopy  by  reflecting  the  light  from  the  mirror 
into  the  patient's  eye,  and  hence  it  is  spoken  of  as 
the  retinal  illumination,  the  "illuminated  area,"  "the 
area  of  light,"  "the  image,"  etc. 

Of  course,  the  form  of  this  illumination  is  con- 
trolled, in  great  part,  by  the  refraction  of  the 
patient's  eye. 

Shadow. — This  is  the  non-illuminated  portion  ol 
the  retina  immediately  surrounding  the  illumination. 


FIG.    10.  Fir,,    ii. 

FIG.  io.— UNIFORM  ILLUMINATION  IN  AN  EMMETROPIC  EYE  WITH  SI.ICHT 

SPHERIC  ABERRATION. 
FIG.  ii. — UNIFORM  ILLUMINATION  AS  IN  FIG.  io,  PASSED  TO  THE  LEFT  BY 

ROTATING  THK    MlRKOR,    DARKNESS   OR    SHADOW   FOLLOWING. 


The  illumination  and  shadow  are,  therefore,  in  con- 
tact, and  the  contrast  is  most  marked  and  easily 
recognized  when  the  illumination  is  brightest.  It  is 
by  this  combination  of  the  illumination  and  non- 
illumination  (shadow)  that  we  study  and  give  the 
"shadow  test"  its  name.  In  the  dark  room,  the 
patient  keeping  his  eye  fixed,  the  retina  is  stationary 
and  in  total  darkness,  except  the  portion  illuminated 


WHERE   TO   LOOK   AND   WHAT   TO   LOOK   FOR.  39 

by  the  light  from  the  mirror  (see  Fig.  10).  Ii  the 
mirror  be  rotated,  the  retinal  illumination  changes 
its  place  (see  Fig.  n)  and  darkness,  or  shadow, 
appears  in  its  stead.  It  is  by  this  change  of  illumina- 
tion and  shadow  (darkness)  that  we  often  speak  of  a 
movement  of  the  shadow. 

Where  to  Look  and  What  to  Look  For. — 
With  the  patient,  the  observer,  and  the  source  of 
light  in  position  as  directed,  the  rays  of  light  are 
reflected  into  the  eye  from  the  mirror  as  it  is  gently 
rotated  in  the  various  meridians,  and  the  (i)  form, 
(2)  direction,  and  (3)  rate  of  movement  of  the  retinal 
illumination  are  carefully  noted  through  a  four-  or 
five-millimeter  area  at  the  apex  of  the  cornea,  as  this 
is  the  part  of  the  refractive  media  in  the  normal  eye 
that  the  patient  will  use  when  the  effects  of  the 
cycloplegic  pass  away  and  the  pupil  regains  its 
normal  size. 

The  one-  or  two-millimeter  area  at  the  edge  of  the 
pupil  should  be  avoided  by  the  beginner,  except  in 
special  instances,  as  only  too  frequently  it  contains 
a  bright  ring  of  light  which  may  or  may  not  give  a 
stronger  refraction  than  the  area  at  the  apex  of  the 
cornea  (see  Spheric  Aberration,  chap.  vi). 


CHAPTER  IV. 

POINT  OF  REVERSAL.-TO  FIND  THE  POINT  OF  REVER- 
SAL.-WHAT  TO  AVOID.-DIRECTION  OF  MOVEMENT 
OF  RETINAL  ILLUMINATION.— RATE  OF  MOVEMENT 
AND  FORM  OF  ILLUM1NATION.-RULES  FOR  LENSES. 
-MOVEMENT  OF  MIRROR  AND  APPARATUS. 

Point  of  Reversal. — This  maybe  stated  in  several 
ways — namely  :  It  is  the  far-point  of  a  myopic  eye,  or 
The  artificial  focal  point  of  the  emergent  rays  of  light 

(Fig.  19),  or 

The  point  where  the  emergent  rays  cease  to  con- 
verge and  commence  to  diverge,  or 
The  point  conjugate  to  a  point  on  the  retina  (Fig. 

23),  or 

The  point  where  the  erect  image  ceases  and  the  in- 
verted image  begins,  or 

The  point  distant  from  the  eye  under  examination, 
where  the  retinal  illumination  can  not  be  seen  to 
move. 

To  Find  the  Point  of  Reversal. — The  recogni- 
tion of  the  point  of  reversal  is  the  principle  of  retinos- 
copy.  It  is  what  is  sought  for,  and,  when  obtained 
under  certain  definite  arrangements,  is  the  correct 
solution  of  the  test.  During  the  test  it  is  easy  to  tell 
when  the  illumination  moves  with  or  against  the  light 
on  the  face,  but  to  get  the  exact  point  where  there 
is  no  apparent  movement  is  not  always  easy,  and  is 

only  acquired  after  careful  practice. 

40 


TO   FIND   THE   POINT  OF   REVERSAL.  41 

For  example,  having  determined  at  one  meter  that 
the  retinal  illumination  with  a  -f-  1.50  D.  in  front  of 
the  observed  eye  just  moves  with  the  light  on  the 
face,  and  against  with  a  +  1.75  D.,  we  know  that  the 
reversal  point  must  be  between  the  strength  of  the 
two  lenses,  or  +  i  .62  D.  This  demonstrates  how  we 
arrive  at  the  exact  correction,  and  also  the  capability 
and  accuracy  of  retinoscopy. 

Emmetropic  and  hyperopic  eyes,  in  a  state  of 
rest,  emit  parallel  and  divergent  rays,  respectively, 
and  to  give  such  eyes  a  point  of  reversal,  or  a  focus 
for  the  emergent  rays,  it  will  be  necessary  to  inter- 
cept these  rays  with  a  convex  lens  as  they  leave 
the  eye.  In  other  words,  emmetropic  and  hyperopic 
eyes  must  be  made  (artificially)  myopic.  In  myopic 
eyes,  however,  the  emergent  rays  always  focus  at 
some  point  inside  of  infinity,  and  the  observer  may, 
therefore,  if  he  is  so  disposed,  by  moving  his  light 
and  mirror  to  or  from  the  patient's  eye,  as  the  case 
may  be,  find  a  point  where  the  retinal  illumination 
ceases  to  move.  If  this  should  be  at  two  meters,  the 
patient  would  have  a  myopia  of  0.50  D.  ;  if  at  four 
meters,  a  myopia  of  0.25  D.  ;  if  at  one  meter,  a 
myopia  of  one  diopter,  etc. 

It  is  well  for  the  beginner  to  remember,  when  using 
the  plane  mirror,  that  the  illumination  on  the  patient s 
face  always  moves  in  the  same  direction  the  mirror 
is  tilted,  but  not  necessarily  so  in  the  pupillary  area, 
where  it  may  appear  to  move  opposite  ;  and  here  it 
is  that  we  speak  of  the  retinal  illumination  moving 
with  or  against  (opposite  to)  the  movement  of  the 

4 


42  RETINOSCOPY. 

mirror,  as  the  case  may  be,  and  make  our  diagnosis 
accordingly. 

As  the  rays  of  light  from  the  mirror  proceed  di- 
vergently to  the  patient's  eye,  as  if  they  came  from 
a  point  back  in  the  mirror  equal  to  the  distance  of 
the  light  (opening  in  light-screen)  in  front  of  it  and 
working  at  one  meter's  distance,  with  source  of  light 
five  inches  in  front  of  the  mirror,  the  rays  appear  to 
emerge  from  a  point  five  inches  back  of  the  mirror, 
or  a  total  distance  of  45  inches  from  the  patient's  eye, 
thus  giving  the  rays  of  light  a  divergence  equal  to 
0.87  of  a  diopter  before  they  reach  the  patient's  eye, 
and  this  point  may  be  made  conjugate  to  the  retina. 
The  observer  will  do  good  work  if  he  reduces  the 
retinal  illumination  to  the  utmost  limit  where  it  can 
be  faintly  seen  moving  with  the  movement  of  the 
mirror,  and  if  this  is  done,  the  observer's  eye  and 
mirror  will  be  just  inside  of  the  point  of  reversal 
where  the  erect  image  can  still  be  recognized.  In 
doing  this,  however,  he  must  allow  0.87  in  his  esti- 
mate and  not  i.o  D. 

At  the  point  of  reversal  no  definite  movement  of 
the  retinal  illumination  is  made  out  and  the  pupillary 
area  is  seen  to  be  uniformly  illuminated,  but  not  so 
brilliantly  as  when  within  or  beyond  the  point  of 
reversal. 

If  the  observer's  eye  is,  at  this  point,  exactly  con- 
jugate to  the  retina,  then  the  movement  of  the  re- 
flected light  on  the  retina  can  not  be  perceived 
(though  it  does  move),  and  the  retinal  illumination 
will  occupy  the  entire  pupil  and  the  shadow  will  be 
absent. 


WHAT   TO   AVOID.  43 

Instead,  however,  of  reducing  the  retinal  illumina- 
tion to  the  utmost  limit  (as  just  mentioned),  where 
it  can  be  faintly  seen  moving  with  the  movement  of 
the  mirror,  the  writer  prefers  and  recommends  plac: 
ing  before  the  eye  under  examination  such  a  lens  or 
series  of  lenses  as  will  bring  the  emergent  rays  of 
light  to  a  focus  on  his  own  retina,  so  that  no  move- 
ment of  the  retinal  illumination  can  be  recognized. 

When  the  point  of  reversal  is  approached,  the 
uniform  color  of  the  retinal  illumination  occupies  so 
much  of  the  pupillary  area  that  the  student  may 
think  he  has  reached  the  point  of  reversal,  and  if  he 
is  not  careful  to  pass  the  retinal  illumination  slowly 
across  the  pupil  and  get  the  shadow,  he  will  find  his 
result  deficient,  and  possibly  miss  seeing  some  small 
amount  of  astigmatism. 

To  make  sure  about  the  point  of  reversal,  it  is  al- 
ways best,  especially  for  the  beginner,  to  keep  put- 
ting on  stronger  neutralizing  lenses  until  he  gets  a 
reversal  of  movement,  when  he  knows  at  once  that 
the  point  of  focus  of  the  emergent  rays  has  passed 
in  between  the  mirror  and  eye  under  examination. 

The  lenses  which  control  the  rays  of  light  emerg- 
ing from  the  patient's  eye  are  spoken  of  as  neutral- 
izing lenses. 

What  to  Avoid. — It  occasionally  happens  that  a 
retinal  vessel  or  vessels  or  a  remnant  of  a  hyaloid 
artery,  if  present,  or  even  the  nerve  head,  may  be 
seen  when  the  light  is  reflected  into  the  eye  ;  if  so, 
they  are  to  be  ignored,  as  they  are  not  parts  of  the 
test.  If  the  patient's  eye  is  turned,  or  the  rays  from 
the  mirror  fall  obliquely,  or  the  neutralizing  lens  in 


44  RETINOSCOPY. 

front  of  the  eye  is  inclined  instead  of  being  perpen- 
dicular, there  will  be  seen  reflections  of  light  and 
images  upon  the  neutralizing  lens  or  cornea,  or  both, 
and,  in  consequence,  the  retinal  illumination  is  more 
or  less  hidden  or  obscured ;  these  images  and  reflec- 
tions can  be  easily  corrected  by  removing  the  cause. 
The  catoptric  images  can  not  be  removed,  but  as 
they  are  very  small,  the  beginner  soon  learns  to 
ignore  them.  The  retinal  illumination  may  occasion- 
ally contain  a  small  dark  center,  which  will  disturb 
the  beginner  unless  he  remembers  that  it  is  caused 
by  the  sight-hole  in  the  mirror,  and  that  it  shows 
particularly  when  the  sight-hole  is  large  and  cut 
through  the  mirror.  This  same  dark  center  in  the 
illumination  is  also  seen  at  times  when  the  light  is 
removed  some  distance  from  the  mirror,  and  the  cor- 
recting lens  almost  neutralizes  the  refraction.  The 
neutralizing  lens  should  never  be  so  close  to  the  eye 
that  the  lashes  touch,  and,  in  warm  weather  especi- 
ally, moisture  from  the  patient's  face  may  condense 
on  the  trial-lens,  and  temporarily,  until  it  is  removed, 
obscure  the  reflex. 

Retinoscopy  with  a  Plane  Mirror  at  One 
Meter's  Distance  and  Source  of  Light  close  to 
the  Mirror. — Direction  of  Movement  of  Retinal 
Illumination. — Rate  of  Movement  and  Form 
of  Illumination. — These  important  points  in  refer- 
ence to  the  retinal  illumination  should  be  decided 
promptly  and  without  any  prolonged  examination. 
This  proficiency,  of  course,  will  only  come  by  prac- 
tice, and  if,  on  first  examination,  the  observer  can 
not  decide  whether  the  retinal  illumination  is  with  or 


FORM   OF   ILLUMINATION.  45 

opposite  to  the  movement  of  the  reflected  light  on 
the  face,  he  may  approach  the  eye  until  this  point  is 
determined.  The  three  important  essentials  may  be 
stated  in  the  following  order  and  in  the  form  of  rules  : 

Direction. — The  recognition  of  the  direction  that 
the  retinal  illumination  takes  when  tilting  the  mirror 
is  a  most  important  point  in  the  study  of  retinoscopy. 

The  movement  of  the  retinal  illumination,  when 
rotating  the  mirror,  going  with  the  movement  of  the 
light  on  the  patient's  face,  signifies  emmetropia, 
hyperopia,  or  myopia,  if  the  myopia  be  less  than  one 
diopter. 

The  apparent  movement  of  the  retinal  illumina- 
tion going  opposite  to  the  movement  of  the  light  on 
the  face  always  signifies  myopia  of  more  than  one 
diopter. 

Rate  of  Movement. — This,  of  course,  is  under 
the  control  and  is  influenced  in  great  part  by  the 
rate  of  movement  of  the  mirror  itself ;  yet  after  a 
little  practice  the  observer  will  recognize  the  fact 
that  there  is  a  certain  slowness  in  the  apparent  rate 
of  movement  of  the  illumination  when  the  refractive 
error  is  a  high  one  and  requires  a  strong  lens  for  its 
neutralization,  whereas  when  the  retinal  illumination 
appears  to  move  fast,  the  refractive  error  is  but 
slight,  and  requires  a  weak  lens  for  its  correction. 

Form  of  Illumination. — A  large,  round  illum- 
ination, while  it  may  signify  hyperopia  or  myopia 
alone,  yet  it  does  not  preclude  astigmatism  in  com- 
bination. 

When  the  illumination  appears  to  move  faster  in 
one  meridian  than  the  meridian  at  right  angles  to  it, 


46  RETINOSCOPY. 

astigmatism  will  be  in  the  meridian  of  slow  move- 
ment. If  the  retinal  illumination  is  a  band  of  light 
extending  across  the  pupil,  it  signifies  astigmatism. 

The  width  of  the  band  of  light  does  not  indicate 
so  much  the  strength  of  the  correcting  cylinder 
required  for  its  neutralization  as  does  the  apparent 
rate  of  movement ;  if  slow,  a  strong,  if  fast,  a  weak, 
cylinder  is  required. 

The  band  of  light  that  is  seen  when  a  spheric  lens 
corrects  one  meridian,  and  the  meridian  at  right 
angles  remains  partly  corrected,  indicates  the  axis  of 
the  cylinder  in  the  prescription. 


FIG.  12. — STRAIGHT  EDGE,  INUICAT-      FIG.   13. — CRESCENT  EDCK,  IM.I- 
ING  ASTIGMATISM.  GATING  SPHERIC  CORRECTION. 


Rules  for  Placing  Neutralizing  Lenses. — A 
plus  lens  is  required  when  the  retinal  illumination 
moves  with  the  illumination  on  the  face,  and  a  minus 
lens  is  required  when  it  moves  opposite  to  the  light 
on  the  face. 

Movement  of  the  Mirror. — There  are  times 
when  a  quick  movement,  and,  at  other  times,  a  slow 
or  gradual  movement,  is  required.  A  substitution  of 
the  quick  for  the  slow  movement,  and  the  result  can 
not  always  be  correct.  This  is  explained  under 
"slow  movement." 

A  quick  movement  may  be  used  when  looking 


MOVEMENT   OF   THE   MIRROR. 


47 


into  the  eye  before  any  correcting  lens  has  been 
placed  in  situ.  It  often  tells  the  character  of  the 
refraction. 

The  slow  movement  comes  into  use  and  is  of 
the  utmost  importance  when  the  eye  has  been  cor- 
rected to  within  0.75  D.  or  less,  as  it  is 
generally  at  this  point  that  so  many, 
by  a    quick   movement,    hasten    the 
peripheral  rays  and  mask  the  central 
illumination,  giving  the  idea  at  once 
of  over-correction  (see  Spheric  Aber- 
ration,   chap.    vi).     This   is   a   most 
common  error  with  the  beginner,  the 
inexperienced,  and  with  those   who 
fail  to  get  good  results  and  who  ridi- 
cule retinoscopy  as  "not  exact,"  or 
as  "  not  agreeing  with  the  subjective 
method."    It  is  well  in  every  instance, 
when   the   point  of   reversal   is    ap- 
proached, to  pass  the  retinal  illumina- 
tion (not  the  light  area  on  the  face) 
well   across   the    pupillary    area    to 
make  sure  in  regard  to  the  character 
of  shadow  which  follows  or  precedes 
it.     This  movement,  at  such  a  point 
in    neutralization,   will   often    give   a 
hint  as  to  the  presence  of  astigma- 
tism or  not,  as  a  reference   to  figures   12  and   13 
will  show.     The  presence  of  astigmatism  is  known 
by  the  straight  edge  of  the  illumination,  or,  in  its 
place,  a  crescent  edge  would  mean  a  spheric  cor- 
rection. 


FIG.  14.  — WORDE- 
MANN'S  Disc. 


RETINOSCOPY. 


Apparatus  for  placing  lenses  in  front  of  the 
patient's  eye. — There  are  several  different  forms  in 
the  market,  their  purpose  being  twofold — to  save 
time  and  any  extra  movements  on  the  part  of  the 


FIG.   15. — JENNINCS'  SKIASCOPIC  Disc. 

surgeon.  Of  these,  that  of  Wiirdemann  (American 
Journal  of  Ophthalmology,  p.  223,  1891)  seems  the 
best  hand  skiascope.  A  reference  to  the  sketch 
shows  this  instrument  with  its  convenient  handle, 


MOVEMENT   OF   THE   MIRROR.  49 

whereby  the  patient,  being  instructed,  raises  or 
lowers  the  disc  in  front  of  the  eye,  with  its  smooth 
broad  edge  resting  against  the  side  of  the  nose. 

One  column  contains  plus  and  the  other  minus 
lenses,  and  as  it  is  reversible,  these  may  be  placed 
in  front  of  the  eye,  as  the  surgeon  directs. 

The  most  modern  and  complete  revolving  skias- 
copic  disc  is  that  of  Jennings  (American  Journal  of 
Ophthalmology,  November,  1896,  and  April,  1899), 
and  may  be  best  understood  from  his  own  descrip- 
tion :  "It  consists  of  an  upright  metal  frame, 
1 8  inches  high  and  7  inches  wide,  placed  at  the 
end  of  a  table  26^  inches  long  and  12  inches 
wide.  In  the  upright  frame  is  an  endless  groove 
containing  39  lenses  and  i  open  cell.  At  the  lower 
end  of  the  frame  is  a  strong  driving  wheel  connected 
with  a  horizontal  rod  running  the  length  of  the  table 
to  a  handle  with  which  the  operator  rotates  the 
lenses.  Facing  the  operator  and  close  to  his  hand 
is  a  large  disc,  on  which  is  indicated  the  lenses  pre- 
sented at  the  sight-hole.  The  white  numbers  on  a 
black  ground  represent  convex,  and  the  black  num- 
bers on  the  white  ground  concave,  lenses.  The 
lenses  range  from  0.25  D.  to  9  D.  plus,  and  from  0.25 
D.  to  9  D.  minus.  The  sight-holes  are  -|  of  an  inch 
in  diameter,  and  are  placed  about  five  inches  from 
the  top  of  the  upright  frame.  In  front  of  each  sight- 
hole  is  a  cell  marked  in  degrees  to  hold  stronger 
spheres  or  cylinders.  The  central  portion  of  the  up- 
right is  cut  away,  leaving  a  space  for  the  face  of  the 
patient.  A  movable  blinder  is  hung  from  the  top 
while  the  chin-rest  moves  up  and  down  on  two  par- 


50  RETINOSCOPY. 

allel  rods  and  is  held  in  place  by  a  thumb-screw. 
The  whole  is  mounted  on  a  strong  adjustable  stand, 
which  is  raised  or  lowered  by  means  of  a  rack  and 
pinion.  The  essential  advantages  of  this  skiascope 
are  as  follows : 

1 .  It  saves  time  and  fatigue  in  changing  lenses. 

2.  It  is  under  the  immediate  control  of  the  operator, 
and    indicates    the    lens  in    front   of  the  sight-hole 
without  his  getting  up. 

3.  The  mechanism  is  simple,  durable,  and  easy  to 
operate. 

4.  The  cornea  is  accurately  centered  and  the  lens 
perpendicular  to  the  front  of  the  eye   (a  very  im- 
portant consideration  and  one  not  possible  with  every 
kind  of  trial  frame). 

5.  The    instrument    is   of  such    length    that    the 
operator   is    always   one    meter   distant    from    the 
patient. 

While  either  the  hand  or  the  revolving  disc  is  rec- 
ommended, yet  the  writer  is  partial  to  an  accurately 
fitting  trial-frame,  using  the  lenses  from  the  trial- 
case,  which  should  be  conveniently  at  hand.  The 
following  suggestions  in  the  selection  and  use  of 
the  trial  frame  are  offered :  The  temples  should  rest 
easily  on  the  ears,  the  nose-piece  (bridge)  to  have 
a  sufficiently  long  post  to  permit  the  eye-pieces  to  fit 
high  and  accurately  over  any  pair  of  eyes,  especially 
those  of  children,  and  have  the  corneae  occupy  the 
center  of  each  eye-piece.  Correct  results  can  not 
be  expected  or  quickly  obtained  unless  the  neutral- 
izing lenses  be  placed  with  their  centers  corre- 
sponding to  corneal  centers,  and  at  the  same  time 
perpendicular  to  the  front  of  the  eye. 


CHAPTER  V. 

RETINOSCOPY    IN     EMMETROPIA    AND    THE    VARIOUS 
FORMS  OF  REGULAR  AMETROPIA.— AXONOMETER. 

Hyperopia. — In  this  form  of  refraction  the  direc- 
tion of  the  movement  of  the  retinal  illumination  is 
with  the  movement  of  the  light  on  the  patient's  face. 
By  rotating  the  mirror  in  the  various  meridians  and 
observing  the  rate  of  movement,  a  strong  or  weak 
plus  sphere,  according  to  the  apparent  rate  of  move- 


FIG.   1 6.  FIG.   17. 

FIG.  16. — GRAY  REFLEX  AS  SEEN  IN  HIGH  HYPEROPIA,  EVEN  DARKER 

THAN    THE   PICTURE    SHOWS    IT. 

FIG.   17. — GRAY  REFLEX,  WITH  CRESCENT  EDGE  BY  TILTING  MIRROR  TO 
LEFT,  DARKNESS  OR  SHADOW  FOLLOWING. 

ment,  is  placed  before  the  eye,  and  the  rate  of  move- 
ment of  the  retinal  illumination  is  again  noted. 

Practice  alone  will  guide  the  observer  in  a  quick 
appreciation  of  the  approximate  strength  of  neutral- 
izing lens  to  thus  employ. 

If  the  movement  of  the  illumination  appears  slow, 
and  the  observer  places  a  -f  2.75  D.  before  the  eye 
for  its  neutralization,  and  the  illumination  then 
becomes  brilliant  and  appears  to  move  fast  and 

5' 


52  RETINOSCOPY. 

with  the  light  on  the  face,  the  hyperopia  is  still 
slightly  uncorrected  and  a  stronger  lens  must  be 
substituted.  (At  this  point  in  the  examination  the 
five-millimeter  opening  in  the  light-screen  may  be 
used  to  advantage.) 

Removing  the  -f-  2.75  D.  and  placing  a  -f  3.25  D. 
in  its  place,  if  the  retinal  illumination  is  found  to 
move  opposite  to  the  movement  of  the  light  on  the 
face,  the  refraction  of  the  eye  will  then  be  between 
the  -f  2.75  D.  and  the  3.25  D.,  which  is  3  D.  (See 
example,  p.  41,  chap,  iv.)  Now,  while  the  +30. 
has  brought  the  emergent  rays  to  a  focus  at  one 


FIG.  18. 

meter,  it  has  made  the  eye  myopic  just  one  diopter, 
so  that  in  taking  the  patient  from  the  dark  room  to 
test  his  vision  at  six  meters,  or  infinity,  this  one 
diopter  (artificial  myopia)  must  be  subtracted  from 
the  +  3  D.,  which  would  leave  +  2  D.,  the  amount 
of  the  hyperopia. 

A  reference  to  figures  18  and  19  will  illustrate  the 
description  just  given. 

Figure  18  is  the  hyperopic  eye  under  examina- 
tion, and  shows  the  mirror  at  one  meter's  distance, 
with  the  light  five  inches  from  the  mirror.  The  dot- 
ted lines  represent  the  rays  proceeding  divergently 


HYPEROPIA.  53 

from  the  eye  under  examination  ;  the  dark  lines  show 
the  reflected  rays  from  the  mirror,  which  illuminate 
the  retina  and  have  an  imaginary  focus  (dotted 
lines)  beyond  the  retina. 

Figure  19  is  a  profile  view  showing  the  hyperopic 
eye  with  neutralizing  lens  in  position.  The  dotted 
lines  with  arrow-heads  indicate  the  direction  the  rays 
would  naturally  take  coming  from  the  eye.  The 
lens  (+3  D.)  in  front  of  the  eye  is  just  sufficiently 
strong  to  bend  these  divergent  rays  and  bring  them 
to  a  focus  at  one  meter's  distance  (artificial  point  of 


i   METER. 


YiG.   19. 


reversal).  In  other  words,  +  2  D.  of  the  three 
diopters  thus  placed  before  this  hyperopic  eye 
would  have  bent  the  divergent  rays  and  made  them 
parallel,  or  emmetropic,  but  the  additional  one 
diopter  bends  the  rays  still  more  and  brings  them 
to  a  focus  (P.  R.)  at  one  meter.  If,  now,  the  ob- 
server approaches  the  eye  thus  refracted  and  ob- 
serves the  retinal  illumination  closer  than  one  meter, 
he  will  be  inside  of  the  point  of  reversal,  and  conse- 
quently see  an  erect  image  moving  rapidly  with  the 
direction  of  the  movement  of  the  mirror.  If  beyond 
this  point  of  reversal,  he  would  get  an  inverted 


54 


RETINOSCOPY. 


image  and  the  retinal  illumination  moving  rapidly  in 
a  direction  opposite  to  the  movement  of  the  mirror. 

Emmetropia. — The  emergent  rays  from  an  em- 
metropic  eye  are  always  parallel,  and  the  observer 
seated  at  one  meter  sees  the  pupillary  area  in  such 
an  eye  brilliantly  illuminated,  the  illumination  mov- 
ing rapidly  with  the  light  on  the  face  as  the  mirror 
is  slowly  rotated. 

A  reference  to  figure  20  shows  the  emmetropic 
eye  under  examination  with  the  position  of  light, 
mirror,  and  eye,  as  in  figure  18.  The  dotted  lines 


Fir,.   20. 

indicate  the  parallel  emergent  rays,  and  the  solid 
lines  the  divergent  rays  from  the  mirror  with  an 
imaginary  focus  just  beyond  the  retina.  The  pur- 
pose in  this  instance,  as  in  all  others  of  retinoscopy, 
is  to  place  such  a  neutralizing  lens  before  the  eye 
as  will  bend  the  emergent  rays  and  bring  them  to 
a  focus  at  a  certain  definite  distance,  making  the 
emergent  rays  from  a  point  on  the  retina  come  to 
a  focus  on  the  observer's  retina.  Therefore,  to 
change  this  illumination  so  that  no  movement  can 
be  seen  to  take  place  in  the  pupillary  area,  and  at 
the  same  time  have  the  emergent  rays  focus  on  the 


MYOPIA.  55 

observer's  retina,   a  +    i    sphere    must   be    placed 
before  the  eye. 

Just  here   the  writer  wishes  to  impress  upon  the 
beginner   the    great  importance,  as   mentioned  on 
page  30,  of  refracting  the  macular  region.     To  ac- 
complish this,  the   patient  must  fix 
his  gaze  upon  the  metal  disc  of  the 
mirror.    As  the  region  of  the  macula 
is    departed    from,   the    strength  of 
the  neutralizing  lens  grows  slightly 
stronger  in   emmetropia  and  hyper- 
opia,  and  diminishes  in  myopia.     A 
reference   to  figure  21  will  give  an 
idea  of  what  is  meant,  and  show  that 
other  radii  are  not  the  same  length  as  the  one  at 
the  fovea. 

Myopia. — In  myopia  the  emergent  rays  always 
converge  to  the  far-point  (point  of  reversal),  and  the 
observer,  seated  at  one  meter  from  the  eye,  will  have 
the  apparent  movement  of  the  retinal  illumination 
going  opposite  to  the  light  on  the  face  if  the  myopia 
exceeds  one  diopter,  and  zvith  the  light  on  the  face  if 
the  myopia  is  less  than  one  diopter.  If  the  myopia 
should  be  just  one  diopter,  then  the  emergent  rays 
would  focus  on  the  observer's  retina  at  one  meter, 
and  there  will  not  be  any  neutralizing  lens  required 
to  accomplish  this  purpose  ;  but  if  the  emergent  rays 
focus  beyond  one  meter,  the  observer  will  be  within 
this  point  of  reversal  or  focus,  and  will,  therefore, 
have  an  erect  image,  moving  fast  with  the  move- 
ment of  the  mirror,  and  will  have  to  place  before 
the  eye  a  plus  lens  of  less  than  one  diopter  to 


56  RETINOSCOPY. 

bring  the  point  of  reversal  up  to  one  meter.  When 
the  myopia  is  more  than  one  diopter,  and  observer 
at  one  meter,  the  emergent  rays  will  have  focused 
somewhere  between  the  observer  and  the  patient, 
and,  as  a  result,  the  retinal  illumination  appears  to 
move  opposite  to  the  light  upon  the  face,  more  or  less 
rapidly,  according  to  the  amount  of  myopia ;  and  a 
concave  or  minus  lens  must  be  placed  in  front  of 
such  an  eye  that  will  bring  the  emergent  rays  to  a 
focus  at  one  meter,  or,  in  other  words,  will  stop  all 
apparent  movement  of  the  retinal  illumination.  If, 


Kin.   22. 


for  example,  a  — 2.75  D.  has  been  so  placed,  and  the 
movement  is  still  slightly  opposite  to  the  movement 
of  the  mirror,  and  a  — 3.25  D.  substituted  makes 
the  retinal  illumination  move  with  the  movement  of 
the  mirror,  then  the  neutralizing  lens  for  one  meter 
would  be  the  difference  between  — 2.75  D.  and 
— 3.25  D.,  which  will  be  — 3  D. 

Figure  22  shows  the  myopic  eye  just  described, 
with  the  position  of  the  mirror,  light,  and  eye,  as  in 
figures  1 8  and  20.  The  solid  lines  represent  the  rays 
reflected  divergently  from  the  mirror  focusing  at  a 
point  in  the  vitreous  before  coming  to  the  retina,  and 


MYOPIA. 


57 


the  broken  lines  show  the  rays  emerging  from  a  point 
on  the  retina  and  then  converging  to  the  focus,  far- 
point,  or  point  of  reversal  close  to  the  eye,  between 
the  eye  and  the  mirror.  The  observer,  seated  with 
the  mirror  one  meter  distant,  gets  an  opposite  move- 
ment in  the  pupillary  area  from  the  direction  in  which 
he  moves  his  mirror,  and,  of  course,  an  inverted 
image.  If  the  observer  had  his  eye  at  the  point 
where  the  emergent  rays  focused  (dotted  lines  cross), 
he  would  not  recognize  any  movement  in  the  pupil- 
lary area,  and  it  would  have  a  uniform  reflex.  The 
amount  of  the  myopia  is  equal  to  the  distance  meas- 


METER 


P.R. 


FIG.  23. 

ured  from  this  point  of  reversal  to  the  cornea ;  for 
example,  if  the  distance  (point  of  reversal)  was 
twenty-five  cm.  from  the  patient's  eye,  then  the 
amount  of  the  myopia  would  be  four  diopters. 

Figure  23  is  a  profile  view  of  the  myopic  eye.  The 
dotted  lines  show  the  rays  coming  from  a  point  on 
the  retina  and  focusing  at  the  far-point  (P.P.);  the 
solid  lines  show  the  emergent  rays  acted  upon  or 
bent  by  a  plano-concave  lens  of  three  diopters, 
which  has  lessened  the  convergence  of  these  emer- 
gent rays  and  put  the  far-point  farther  from  the  eye, 
or  at  a  distance  of  one  meter.  The  observer  at 


58  RETIXOSCOPV. 

this  distance  does  not  appreciate  any  movement  in 
the  pupillary  area,  but  if  he  moves  the  light  and 
mirror  closer  to  the  eye  he  is  then  inside  the  point 
of  reversal  and  gets  an  erect  image  moving  with  the 
movement  of  the  mirror;  if  beyond  the  one  meter's 
distance,  an  inverted  image  and  movement  against 
the  movement  of  the  mirror  will  be  seen.  If  a  — 4  D. 
lens  had  been  placed  before  this  myopic  eye,  the 
emergent  rays  would  have  proceeded  from  it  par- 
allel, and  the  observer,  at  one  meter,  would  have  the 
same  conditions  as  in  the  refraction  of  an  emme- 
tropic  eye,  figure  20 ;  but  as  only  a  — 3  D.  glass  was 
used,  the  eye  has  one  diopter  of  its  myopia  uncor- 
rected.  From  the  description  of  retinoscopy  in 
hyperopia,  emmetropia,  and  myopia,  just  given,  the 
student  will  recognize  at  once  that  the  hyperopic, 
emmetropic,  and  myopic  eye  of  less  than  one 
diopter,  working  with  the  plane  mirror  at  one  meter's  f 
distance,  are  given  a  stronger  refraction  than  they 
naturally  call  for,  or,  in  other  words,  are  made,  artifi- 
cially, myopic  one  diopter.  And  the  myopic  eye  of 
more  than  one  diopter,  under  similar  conditions, 
being  already  myopic,  retains  one  diopter  of  its 
myopia.  To  give  a  patient  thus  refracted  with  the 
retinoscope  his  emmetropic  correction  (correction  for 
parallel  rays  of  light),  an  allowance  must  always  be 
made,  in  all  meridians,  of  one  diopter,  no  matter  what 
the  refraction.  The  artificial  myopia  thus  produced 
at  one  meter  gives  the  following  rules  for  glasses 
required  for  infinity : 

Rules. —  i.  When  the  neutralizing  lens  employed 
is  plus,  then  subtract  one  diopter. 


REGULAR    ASTIGMATISM.  59 

2.  When  the  neutralizing  lens  employed  is  minus, 
then  add  a  — i  D.,  or  what  is  more  simple,  or  even  a 
better  rule,  is,  To  always  add  a  — /  sphere  to  the 
neutralizing  lens  obtained  in  the  dark  room  when 
working  at  one  meter,  and  the  result  will  be  the 
emmetropic  or  infinity  correction. 

Examples  : 

DARK  ROOM, -(-0.50      o.oo  -f1-00  +2.00  — i.oo 

ADDING, — i.oo — i.oo — i.oo — i.oo — i.oo 


EMMETROPIC  CORRECTION, — 0.50  — i  oo  — o.oo  -j-i.oo  — 2.00 

The  main  point  in  all  retinoscopic  work  to  remem- 
ber in  changing  from  the  dark  room  to  the  six  meter 
correction,  is  to  always  alloivfor  the  distance  from  the 
patient 's  eye  to  the  point  of  reversal — i.  e.,  if  working 
at  half  a  meter,  allow  two  diopters  ;  if  at  two  meters, 
0.50  D.;  if  at  four  meters,  0.25  D.,  etc. 

Regular  Astigmatism. — When  refracting  with 
the  retinoscope,  the  observer  should  remember  that 
he  is  refracting  the  meridian  in  the  direction  of  which 
he  moves  the  mirror.  Particular  attention  is  called 
to  this  important  fact  on  account  of  the  confusion 
sometimes  arising  in  the  student's  mind  from  the 
use  of  the  ophthalmoscope,  where  the  refractive 
condition  of  a  certain  meridian  is  studied  by  the 
appearance  of  the  vessels  at  right  angles  to  it. 
Astigmatism  being  present  in  an  eye,  means  a  differ- 
ence in  the  strength  of  the  glass  required  for  the 
two  principal  meridians,  which,  with  few  exceptions, 
are  at  right  angles  to  each  other,  and  it  is  to  these 
two  principal  meridians  only  that  the  observer  pays 


60  RETINOSCOPY. 

attention  ;  for  example,  the  eye  that  takes  the  follow- 
ing formula, 

-\-  i.oo  D.  Q  -f  i. oo  c.  axis  105°, 

means  that  in  the  105  meridian  there  is  +  i  D.  and 
in  the  15  meridian  a  -f  2  D.  In  the  dark  room  a 
-f  2  sphere  in  front  of  such  an  eye  at  one  meter 
would  correct  the  105  meridian  and  partly  correct 
the  15  meridian  ;  or  a  4-  3  D.  would  correct  the  15 
and  over-correct  (movement  against)  the  105  mer- 
idian. When  with  -i-  2  D.  the  105  meridian  is  cor- 


+3.D 


rected  and  the  1 5  only  partly  so,  there  is  seen  in  the 
1 5  meridian  a  band  of  light  which  stands  or  extends 
across  the  pupil  in  the  105  meridian  and  moves 
across  the  pupil  from  left  to  right  with  the  move- 
ment of  the  mirror  as  it  is  tilted  in  the  15  meridian. 
The  presence  of  this  band  of  light  after  the  mer- 
idian of  least  ametropia  has  been  corrected  always 
signifies  astigmatism,  and  the  axis  it  subtends — in 
this  case  105° — gives  the  axis  of  the  cylinder  in  the 
prescription  ;  and  the  amount  of  the  astigmatism,  or 
the  strength  of  the  cylinder  required,  is  the  differ- 


REGULAR   ASTIGMATISM.  61 

ence  between  the  strength  of  the  two  spheres  em- 
ployed. Figure  24  shows  the  method  of  writing 
such  a  dark  room  correction,  and  adding,  according 
to  our  rule,  a  — i  to  this  dark  room  work,  we  get 
our  original  formula : 

-f-  i.oo  D.  0  -(-  i.oo  c.  axis  105°. 

The  method  of  correcting  with  spheres  will  be  found 
much  more  satisfactory  than  by  placing  a  -f-  2  D., 
as  called  for  in  the  105  meridian,  then  adding  and 
changing  cylinders  until  the  correct  one  is  found. 


FIG.  25.  FIG.  26. 

FIG.  25. — BAND  OK  LIGHT  AT  Axis  60°,  WITH  THE  60°  MERIDIAN  NEU- 
TRALIZED. No  movement  of  the  illumination  can  be  recognized  in  this 
meridian. 

FIG.  26. — Shows  the  same  as  figure  25,  but  the  band  of  light  with  straight 
edge  has  been  moved  upward  and  to  the  left  by  tilting  the  mirror  in  the 
150°  meridian. 


It  takes  much  time  and  care  to  get  the  cylinder  axis 
just  right,  and  is  most  difficult  in  the  dark  room. 
After  the  result  has  been  obtained  with  spheres,  the 
observer  may,  if  he  is  so  disposed,  prove  it  before 
leaving  the  dark  room  with  the  sphere-cylinder 
combination. 

Astigmatism  may  or  may  not  be  recognized  on 
first  inspection  of  the  fundus-reflex,  this  depending 
entirely  on  the  refraction  ;  if  it  be  a  high  astigmatism 
with  a  small  amount  of  refractive  error  in  the  op- 


62  RETINOSCOPY. 

posite  meridian,  as  in  one  of  the  following  formulas. 

+  i. oo  D.  C  +  3.00  c.  axis    45°, 

-  i. oo  D.  Q  —  4-oo  c.  axis  180°, 

then  the  band  of  light  so  characteristic  of  astigma- 
tism will  be  plainly  seen  on  first  inspection,  extend- 
ing across  the  pupil  before  any  neutralizing  lens  has 
been  placed  in  position  ;  but  if  the  hyperopia  or  my- 
opia be  high  and  the  cylinder  required  is  low,  as  in 
one  of  the  following  formulas, 

+  3.00  D.  O  -f  0.75  c.  axis  105°, 

-  4.00  D.  Q  —  i. oo  c.  axis  165°, 

then  the  band  of  light  is  not  recognized  on  first  in- 
spection or  until  an  approximate  correction  has 
been  placed  before  the  eye.  To  get  an  idea  of 
what  the  band  of  light  looks  like,  the  beginner  may 
refer  to  figures  25  and  27;  or  focus  rays  of  light 
through  a  strong  cylinder ;  or 
place  a  cylinder  in  front  of  the 
schematic  eye  and  study  the 
retinal  illumination.  The  stu- 
dent should  bear  in  mind  that 
the  axis  of  the  band  of  light 
appears  on  the  meridian  of 

FIG.  27. — BAND  OF  LIGHT.     ,  .  ,    .      ,     .    , 

ASTIGMATISM  AXIS  90°.  least  ametropia,  and  is  bright- 
est when  this  meridian  has  re- 
ceived its  full  spheric  correction — the  opposite 
meridian  being  only  partly  corrected. 

The  reason  for  the  brightness  of  the  band  of  light 
when  the  meridian  of  its  axis  is  corrected  is  that 
any  point  on  the  retina  in  this  meridian  is  conjugate 
to  the  focus  on  the  observer's  retina  (point  of  re- 


MIXED   ASTIGMATISM.  63 

versal),  and  any  movement  of  the  mirror  in  this 
meridian  is  not  recognized,  but  has  a  uniform  color 
and  occupies  the  entire  meridian  of  the  pupil.  To 
recognize  so  small  an  error  as  a  quarter  diopter 
cylinder, — which  is  not  easily  detected,  and  the 
observer,  if  he  is  in  a  hurry,  might  think  the  case 
one  of  simple  hyperopia  or  myopia, — the  writer 
would  suggest  that  when  the  supposed  point  of 
reversal  is  reached  the  correcting  sphere  be  in- 
creased a  quarter  of  a  diopter,  and  if  only  one 
meridian  is  found  over-corrected  (movement  oppo- 
site), the  other  remaining  correct  (no  movement 


FIG.  28. — BAND  OF  LIGHT  SHOWING  HALF  A  DIOPTER  OF  ASTIGMATISM. 

recognized),  he  then  knows  that  a  quarter  cylinder 
is  required  ;  for  example,  a  -f  2  D.  is  supposed  to 
correct  all  meridians,  and  yet  by  substituting  a 
-f  2.25  D.,  the  vertical  meridian  moves  against  and 
the  horizontal  remains  stationary;  then  a  -f  0.25  D. 
cylinder  is  called  for  at  axis  90°. 

Cases  having  a  low  astigmatic  error  of  0.50  D. 
can  be  recognized  when  near  the  point  of  reversal 
by  the  faint  shaded  area  on  each  side  of  the  band 
of  light,  as  shown  in  figure  28 — a  condition  often 
overlooked. 

Mixed  Astigmatism. — In  this  condition  of  re- 
fraction, where  one  meridian  is  myopic  and  the 


64  RETINOSCOPY. 

meridian  at  right  angles  to  it  is  hyperopic,  the  move- 
ment of  the  retinal  illumination  in  the  myopic  meri- 
dian will  be  controlled  by  the  amount  of  the  myopia. 
The  illumination  in  the  myopic  meridian,  if  the  my- 
opia is  less  than  one  diopter,  moves  with  the  mirror, 
and  against  the  movement  of  the  mirror  if  it  is  more 
than  one  diopter ;  in  either  instance  the  observer 
gets  a  distinct  band  of  light  in  the  meridians  alter- 
nately as  each  meridian  is  neutralized  separately  with 
a  sphere.  Taking  the  following  example, 

— 2.00  c.  axis  180°  Q  -(-  i.oc  c.  axis  90°, 

the  90  meridian  shows  an  opposite  movement,  and 
in  the  horizontal  the  movement  is  with  the  move- 
ment of  the  mirror.  If,  now,  a  — i  D.  sphere  be 
placed  before  the  eye,  the  90  meridian  is  neutralized 
for  one  meter  distance,  and  a  bright  band  of  light  is 
seen  at  90°,  moving  with  the  movement  of  the 
mirror  on  the  horizontal  meridian.  Removing  the 

—  i  D.  and  placing  a  +  2  D.  before  the  eye,  which 
would    neutralize  the   horizontal    meridian    for  one 
meter,  a  bright  band  will  be  seen  on  the  horizontal 
axis  and  moving  opposite  to  the  movement  of  the 
mirror  in  the  90°  meridian.     Carrying  out  the  rule 
of  always  adding  a  — i  D.  sphere  to  the  correction 
obtained  in  the  dark  room  at  one  meter,  we  have 

—  i    added    to    the  — i    in    the   vertical    meridian, 
making — 2   D.,  axis   180°;  and  adding  — i  to  the 
-f  2  D.  in  the  horizontal,  we  have  +  i    D.  for  axis 
90°,  or  our  original  formula  : 

— 2.00  axis  180°  Q  -)-  i.oo  c.  axis  90°. 
The  rule  for  neutralizing  lenses  in  mixed  astigma- 


AXONOMETER.  65 

tism  is  the  same  as  for  any  other  form  of  refraction  ; 
namely,  using  a  plus  lens  when  the  movement  is 
with,  and  a  minus  lens  when  the  movement  is  oppo- 
site to,  the  movement  of  the  light  on  the  face. 

Axonometer. — To  find  the  exact  axis  subtended 
by  the  band  of  light  while  studying  the  retinal  illumi- 
nation, when  the  meridian  of  least  ametropia  has 
been  corrected,  the  writer  has  suggested  a  small  in- 
strument which,  for  want  of  a  better  name,  he  has 
called  an  axonometer. 

Figure  29  shows  this  instrument,  and  figure  30  the 
axonometer  in  position. 

The  description  of  this  device  was  published  in 
The  Medical  News,  March  3,  1894,  as  follows  :  "  The 
direction  of  the  principal  meridians  of  corneal  curva- 
ture is  often  difficult  to  determine,  and  the  state- 
ment of  the  patient  must  be  accepted  when  confirm- 
ing the  shadow-test  correction  ;  or,  if  there  is  still 
uncertainty,  the  ophthalmometer  of  Javal  may  be  of 
service.  The  axonometer  is  a  black  metal  disc, 
with  a  milled  edge,  one  and  one-half  mm.  in  thick- 
ness, of  the  diameter  of  the  ordinary  trial-lens,  and 
mounted  in  a  cell  of  the  trial-set.  It  has  a  central 
round  opening  1 2  mm.  in  diameter — the  diameter 
of  the  average  cornea  at  its  base.  Two  heavy 
white  lines,  one  on  each  side,  pass  from  the  circum- 
ference across  to  the  central  opening,  bisecting  the 
disc.  To  use  the  axonometer,  place  it  in  the  front 
opening  of  the  trial-frame,  and  with  the  patient 
seated  erect  and  frame  accurately  adjusted  so  that 
the  cornea  of  the  eye  to  be  refracted  occupies  the 
central  opening,  proceed  as  in  the  usual  method  of 


66  RETINOSCOPY. 

making  the  shadow  test.     As  soon  as  that  lens  is 
found  which  corrects  the  meridian  of  least  ametropia, 


FIG.  29. 


and  the  band  of  light  appears  distinct,  turn  the 
axonometer  slowly  until  the  two  heavy  white  lines 
accurately  coincide,  or  appear  to  make  one  continu- 
ous line  with  the  band  of  light  (see  Fig.  30). 


FIG.  30. 

"  The  degree  marks  on  the  trial-frame   to  which 
the  arrow-head  at  the  end  of  the  white  lines  then 


AXONOMETER.  67 

points  is  the  exact  axis  for  the  cylinder.  The  axo- 
nometer  possesses  the  following  points  of  merit : 

"Simplicity. 

"  Accuracy. 

"  Small  expense. 

"  It  covers  an  unnecessary  part  of  the  trial-lens 
which  too  frequently  gives  annoying  reflexes  and 
images. 

"  It  saves  time,  avoids  the  statement  of  the  patient, 
and  renders  the  ophthalmometer  unnecessary. 

"Its  color  (black)  absorbs  the  superfluous  light 
rays  from  the  mirror  and  gives  a  stronger  contrast 
to  the  reflex  and  central  illumination. 

"  Limiting  the  field  of  vision  in  children,  it  permits 
of  more  concentrated  attention. 

"  For  children  and  nervous  patients,  when  it  is 
difficult  to  use  the  ophthalmometer,  this  simple 
appliance  is  of  great  service." 


CHAPTER  VI. 

RETINOSCOPY  IN  THE  VARIOUS  FORMS  OF  IRREGULAR 
AMETROPIA.  —  RETINOSCOPY  WITHOUT  A  CYCLO- 
PLEGIC.  —  THE  CONCAVE  MIRROR.  —  DESCRIPTION 
OF  THE  AUTHOR'S  SCHEMATIC  EYE  AND  LIGHT- 
SCREEN.-LENSES  FOR  THE  STUDY  OF  THE  SCISSOR 
MOVEMENT,  CONIC  CORNEA,  AND  SPHERIC  ABERRA- 
TION. 

Irregular  Astigmatism. — This  condition  is 
either  in  the  cornea  or  in  the  lens ;  in  any  instance 
it  is  confusing  to  the  beginner,  and  even  the  expert 
must  work  slowly  to  obtain  a  result.  The  corneal 
form  is  most  difficult  to  refract,  as  the  retinal  illumi- 
nation is  more  or  less  obscured  by  areas  of  darkness. 
The  illumination  between  these  dark  areas  appears 
to  move  with,  in  places,  and  in  others  against,  the 
movement  of  the  mirror.  By  moving  the  mirror  so 
as  to  make  the  light  describe  a  circle  around  the 
pupillary  edge,  a  most  unique  kinetoscopic  picture  is 
obtained,  which  is  quite  diagnostic  of  the  condition. 
To  refract  an  eye  with  this  irregularity  the  observer 
may  have  to  change  his  position  several  times,  going 
closer  to  or  farther  away  from  the  patient.  Very 
often  these  eyes  are  astigmatic,  and  the  band  of  light 
may  be  promptly  noted  by  the  observer  changing 
his  position  as  suggested,  and  at  the  same  time  plac- 
ing a  neutralizing  lens  in  position.  Care  must  be 
taken,  also,  to  refract  in  the  area  of  the  cornea  that 
will  correspond  to  the  small  pupil  when  the  effect  of 

68 


IRREGULAR  ASTIGMATISM.  69 

the  cycloplegie  passes  away.  It  is  often  best,  in 
these  cases  of  irregular  corneal  astigmatism,  to  retain 
the  correction  found  and  use  it  to  assist  in  a  post- 
cycloplegic  manifest  refraction. 

Irregular  astigmatism  of  the  lens  is  frequently 
more  or  less  uniform,  and  not  so  broken  as  in  the 
corneal  variety.  Figures  31  and  32  show  two  kinds 
of  irregular  lenticular  astigmatism. 

Figure  31  illustrates  the  spicules  pointing  in  from 
the  periphery,  and  so  long  as  these  do  not  encroach 
upon  the  pupillary  area,  they  do  not  usually  in  them- 
selves interfere  with  vision ;  they  are  not  often 


FIG.  31.  FIG.  32. 

IRREGULAR  LENTICULAR  ASTIGMATISM. 

recognized  until  the  pupil  is  dilated,  are  then  very 
faint,  and  not  usually  made  out  until  the  point  of 
reversal  is  approached.  Figure  32  is  another  form 
of  irregular  lenticular  astigmatism,  and  a  very  inter- 
esting picture  as  studied  with  the  retinoscope ;  and, 
as  in  figure  31,  zvhen  very  faint,  is  not  made  out 
until  close  to  the  point  of  reversal.  These  two 
forms  of  irregular  lenticular  astigmatism,  when  just 
beginning,  are  very  seldom  seen  with  the  ophthal- 
moscope ;  the  striations  are  too  fine  to  be  made  out 
except  under  the  conditions  just  described,  and  when 
recognized  are  of  inestimable  value  from  a  point  of 
prophylactic  treatment,  calling  for  a  change  of  occu- 


70  RETINOSCOI'V. 

pation,  rest  to  the  eyes,  and  carefully  selected  glasses, 
the  latter  often  being  weak  lenses.  These  lenticular 
conditions  not  infrequently  accompany  the  "  flannel- 
red  "  fundus,  the  "fluffy  eye  ground,"  the  "shot-silk 
retina,"  the  "  woolly  choroid,"  etc. 

Scissor  Movement. — Another  form  of  astig- 
matism that  may  be  classed  as  irregular  is  where 
there  are  two  areas  of  light,  each  with  a  straight  edge, 
and  usually  seen  on  the  horizontal  meridian,  or 
inclined  a  few  degrees  therefrom  either  way,  and 
moving  toward  each  other  as  the  mirror  is  tilted  in 


FIG.  34. — LIGHT  AREAS  CO.MIM;  TOGETHER  AND  DARK  INTERSPACE 

FADING. 

the  opposite  meridian  ;  in  other  words,  as  the  ob- 
server is  seated  at  one  meter  he  sees  an  area  of 
light  above  and  an  area  of  light  below  with  a  dark 
interspace  (Fig.  33).  As  the  mirror  is  slowly  tilted 
in  the  vertical  meridian  these  light  areas  approach 
and  are  followed  by  darkness  or  shadow,  and  at  the 
same  time  the  dark  interspace  begins  to  fade,  giving 
the  picture  as  shown  in  figure  34.  When  the  light 
areas  are  brought  together,  they  result  in  a  hori- 
zontal band  of  light,  as  seen  in  figure  35,  and  at  this 
point  resemble  the  ordinary  band  of  light  as  seen  in 
regular  astigmatism.  This  movement  of  the  light 


SCISSOR   MOVEMENT.  71 

areas  is  likened  to  the  opening  and  closing  of  the 
scissor  blades,  and  hence  the  name  of  scissor  move- 
ment. 

These  cases  are  more  or  less  difficult  to  refract, 
but  the  presence  of  the  two  areas  of  light  with  the 
dark  interspace  will  often  assist  in  a  correct  selec- 
tion of  glasses,  for  while  they  are  generally  of  the 
compound  hyperopic  variety,  calling  for  a  plus 
sphere  and  plus  cylinder,  yet  practice  and  the  patient's 


FIG.   33.  TIG.  35. 

FIG.  33. — LIGHT  AREA  ABOVE  AND  BELOW,  WITH  DARK  INTERSPACE. 
FIG.  35. — LIGHT  AREAS  BROUGHT  TOGETHER. 

statement  often  call  for  a  plus  sphere  and  minus 
cylinder. 

With  the  following  formula, 

-\-  2.00  D.  Q  -f-  0.75  c.  axis  90°, 

substituting  a  sphere  the  strength  of  the  combined 
values  of  the  sphere  and  cylinder,  and  using  a  minus 
cylinder  of  the  same  number  as  the  plus  cylinder 
at  the  opposite  axis,  the  result  will  be, 

-j-  2.75  D.  Q  —  0.75  c.  axis  180°. 

The  vision  with  the  latter  formula  is  much  better 
in  many  instances  than  with  the  former,  and  though 
either  formula  would  be  correct,  yet  the  latter  is 
practically  the  better  of  the  two,  and  should  be 
ordered  when  so  found.  The  condition  which  may 


72  RETINOSCOl'Y. 

be  the  probable  cause  of  the  scissor  movement  is  a 
slight  tilting  of  the  lens  (see  Fig.  36) — that  is,  the 
antero-posterior  axis  of  the  lens  does  not  stand 
perpendicular  to  the  plane  of  the  cornea,  thus  mak- 
ing one  portion  of  the  pupil  myopic  (area  of  light 
moving  opposite)  and  the  other  portion  hyperopic 
(area  of  light  moving  with  the  movement  of  the 
mirror).  This  condition  may  be  simulated  by  plac- 
ing a  convex  lens  at  an  angle  before  the  schematic 
eye,  or  reflecting  the  light  into  the  eye  obliquely, 
or  by  using  the  combination  lens  in  front  of  the 
schematic  eye,  as  suggested  on  page  81.  What 


causes  the  tilting  of  the  lens  the  writer  is  not 
prepared  to  state  positively ;  it  may  be  congenital, 
and  yet  careful  'inquiry  of  the  patients,  in  many 
instances,  has  shown  that  it  is  most  likely  due  to 
using  the  eyes  to  excess  in  the  recumbent  posture. 
It  may  be  a  coincidence,  but  most  of  the  cases  of 
scissor  movement  seen  by  the  author  have  been  in 
adults,  and  those  who  were  in  the  habit  of  reading 
while  lying  down,  reading  themselves  to  sleep  at 
night  in  bed.*  Other  cases  were  seen  among 

*  The  writer  does  not  wish  to  be  misunderstood  and  does  not 
say  that  every  one  who  uses  his  eyes  in  this  faulty  position  must 
develop  this  form  of  irregular  astigmatism. 


COMPOUND   IRREGULAR   ASTIGMATISM.  73 

paper-hangers,  whose  occupation  compelled  them  to 
look  upward  much  of  the  time.  These  do  not  seem 
unlikely  causes,  especially  when  the  anatomy  of  the 
ciliary  region  is  considered,  the  strain  of  the  accom- 
modation (possibly  spasm)  during  the  faulty  position 
of  the  eye  tilting  the  lens  as  it  rests  upon  the 
vitreous  body.  This  form  of  astigmatism,  so  far 
as  known,  remains  a  permanent  one  even  after  a 
cessation  from  the  original  cause  and  correcting 
glasses  have  been  ordered.  The  retinoscope  is  the 
only  instrument  of  precision  we  have  in  diagnosing 
this  condition.  The  ophthalmoscope  may  recognize 


FIG.  37. 

the  presence  of  the  astigmatism,  but  not  its  char- 
acter, and  the  ophthalmometer  only  records  the 
corneal  curvature.  Cases  of  aphakia  (following 
cataract  extraction]  frequently  show  the  scissor 
movement  during  the  process  of  retinoscopy.  This 
is  undoubtedly  due  to  the  flattening  of  the  cornea 
corresponding  to  the  section,  making  one  portion 
myopic  and  the  other  hyperopic.  Figure  37  shows 
such  a  condition,  where  the  upper  illumination  would 
move  with  and  the  lower,  being  myopic,  would  move 
against  the  movement  of  the  mirror. 

Compound    Irregular   Astigmatism. — This  is 
a  combination  of  the  scissor  movement  and  regular 

7 


74  RETINOSCOPY. 

astigmatism,  but  they  are  not  at  right  angles  to  each 
other.  The  scissor  movement  may  be  at  180°,  and 
the  regular  astigmatism  at  some  point  away  from 
90°,  but  not  at  90°  ;  or  the  regular  astigmatism  may 
be  at  90°  and  the  scissor  movement  at  some  meri- 
dian other  than  180°. 

A  hasty  review  of  the  literature  of  astigmatism 
does  not  reveal  any  reference  to  this  form,  and  the 
name  for  the  condition  has  been  suggested  by  the 
following  picture,  namely :  When  studying  the  reflex, 
a  vertical  band  of  light  will  be  seen  passing  across 
the  pupillary  area  from  left  to  right  as  the  mirror  is 
turned,  and  then  in  the  vertical  meridian  (not  at 
right  angles)  the  scissor  movement  will  be  recog- 
nized also ;  there  is,  therefore,  a  combination  of 
regular  corneal  astigmatism  with  the  scissor  move- 
ment at  an  oblique  angle,  giving  the  compound 
name  suggested.  This  form  of  astigmatism  is  rare, 
yet  not  difficult  to  diagnose  or  refract  when  under- 
stood. It  is  hoped,  however,  that  the  beginner  in 
retinoscopy  may  not  meet  one  of  these  on  his  first 
attempt  at  the  human  eye.  (See  page  83.) 

Conic  Cornea. — Reflecting  the  light  into  an  eye 
that  has  such  a  condition,  the  observer  is  impressed 
at  once  with  the  bright  central  illumination  that 
moves  opposite  to  the  movement  of  the  mirror,  the 
peripheral  illumination  moving  with,  unless  perchance 
the  margin  should  be  myopic  also,  but  of  less  degree. 
This  form  of  illumination  is  seen  in  figure  38,  showing 
the  central  illumination  faintly  separated  by  a  shaded 
area  or  ring  from  the  peripheral  circle.  The  best 
way  to  refract  a  case  of  this  kind  is  to  keep  a  record 


SPHERIC   ABERRATION.  75 

of  the  neutralizing-  lens  or  lenses  required  for  the 
portion  of  the  pupillary  area  that  will  correspond  to 
the  size  of  the  pupil  after  the  effect  of  the  cycloplegic 
passes  away,  and  use  this  record  as  a  guide  in  a 
post-cycloplegic  manifest  correction,  as  in  irregular 
corneal  astigmatism. 

As  the  apex  of  the  cone  is  not  always  central,  the 
observer  must  not  expect  to  always  find  the  bright 
illumination  in  the  center  of  the  pupillary  area,  as 
just  mentioned  ;  and  it  is  also  well  to  note  the  fact 
that  a  band  of  light  will  often  appear  during  the 


FIG.  38. — ILLUMINATION  SEEN  IN  CONIC  CORNEA. 

process  of  neutralization,  as  astigmatism  is  usually 
present.     This  is  further  described  on  page  82. 

Spheric  Aberration. — This  appears  under  two 
forms,  positive  or  negative,  and  is  the  condition  in 
which,  during  the  process  of  neutralization,  there  are 
two  zones,  one  central  and  the  other  peripheral, 
where  the  refraction  is  not  the  same.  In  positive 
aberration  the  peripheral  refraction  is  stronger  and 
in  negative  aberration  the  peripheral  is  weaker  than 
the  central  area  ;  that  is  to  say,  in  the  positive  form, 
when  the  point  of  reversal  for  the  center  of  the  pupil 
is  close  to  one  meter,  the  peripheral  illumination 
grows  broader  and  has  a  tendency  to,  and  often  will, 
crowd  in  upon  the  small  central  illumination,  giving 


76 


RETINOSCOPY. 


the  idea  of  neutralization,  or  even  the  appearance 
of  over-correction,  the  illumination  in  the  periphery 
moving  opposite.  The  observer  must  be  on  his 
guard  for  this  condition,  and  while  giving  the  mirror 
a  slow  and  limited  rotation  must  watch  carefully  the 
illumination  in  the  center  of  the  pupil  and  not  hasten 


FIG.  39. — POSITIVE  AHERRATION. 

the  peripheral  movement.  (See  What  to  Avoid, 
p.  26,  chap,  iv.)  The  observer  may  have  to  ap- 
proach the  patient's  eye  closer  than  one  meter  if  the 
peripheral  illumination  appears  to  move  very  fast. 
The  negative  form  is  where  the  peripheral  refraction 
is  weak  as  compared  to  the  central,  which  appears 


FIG.  40. — NEGATIVE  ABERRATION. 

strong,  and  when  the  neutralizing  lens  gives  a  point 
of  reversal  at  the  center  of  the  pupil  the  peripheral 
illumination  still  moves  with  the  movement  of  the 
mirror.  This  condition  is  seen  in  cases  of  conic 
cornea. 

Figure  39  illustrates  positive  aberration  where  the 


RETINOSCOPY   WITHOUT   A   CYCLOPLEGIC.  77 

parallel  rays  passing  through  a  convex  lens  in  the 
periphery  at  A  A  come  to  a  focus  at  A',  much 
sooner  than  the  parallel  rays  B  B,  near  the  center, 
which  come  to  a  focus  back  of  A'  at  B', 

Figure  40  illustrates  negative  aberration,  which  is 
the  reverse  of  positive  aberration,  and  the  central 
rays  B  B  are  focused  at  B'  in  front  of  the  peripheral 
rays  A  A  focusing  at  A '. 

Retinoscopy  Without  a  Cycloplegic. — Cases 
of  myopia  and  mixed  astigmatism  which  have 
large  pupils  can  be  quickly  and  accurately  re- 
fracted by  the  shadow  test  without  the  use  of  a 
cycloplegic.  This  has  been  repeatedly  proven  by 
comparison  of  the  manifest  and  cycloplegic  results  ; 
yet  it  is  not  a  method  to  be  recommended  or  pur- 
sued, for  two  reasons  :  One  is  that  these  patients 
are  not  annoyed,  like  hyperopics,  by  the  blurred  near- 
vision  incident  to  the  cycloplegic  ;  and,  secondly, 
glasses  ordered  without  the  cycloplegic  seldom  give 
the  comfort  that  follows  from  the  physiologic  rest 
the  eye  receives  from  the  drug.  The  surgeon  will 
obtain  much  assistance  and  save  time  by  using  the 
retinoscope  in  cases  of  aphakia,  in  old  persons 
especially  who  are  very  slow  to  answer,  and  will 
insist  upon  a  description  of  what  they  do  and  do 
not  see,  as  also  in  re-reading  the  test-card  from  the 
very  top  each  time  a  change  of  lens  is  put  in  the 
trial-frame.  Presbyopes  of  fifty  or  more  years  of 
age  can  be  quickly  and  not  inconveniently  refracted 
by  the  shadow  test  after  having  their  pupils  dilated 
with  a  weak  (four  per  cent.)  solution  of  cocain. 


78  RETINOSCOPY. 

Concave  Mirror. — While  the  study  of  retinos- 
copy  with  the  concave  mirror  is  not  a  part  of  the  sub- 
ject of  this  book,  and  allusion  to  it  has  been  carefully 
avoided  up  to  this  time,  yet  for  the  benefit  of  those 
who  may  wish  to  try  it,  the  writer  would  suggest 
that  it  will  be  necessary  to  place  the  source  of  light 
(20  or  30  mm.  opening  in  light-screen)  above  and 
beyond  the  patient's  head,  one  meter  distant,  or  more, 
so  that  the  convergent  rays  from  the  mirror  come  to 
a  focus  and  cross  before  entering  the  observed  eye. 
Then  to  estimate  the  refraction,  proceed  as  with 
the  plane  mirror,  remembering,  however,  that  the 
movements  of  the  retinal  illumination  are  just  the 
reverse  of  those  obtained  when  using  the  plane 
mirror. 

The  Author's  Schematic  Eye  for  Studying 
Retinoscopy. — For  illustration  see  figure  i  and  the 
Journal  of  the  American  Medical  Association,  Janu- 
uary5, 1895.  The  eye  as  here  shown,  slightly  reduced 
in  size,  is  made  of  two  brass  cylinders,  one  somewhat 
smaller  than  its  fellow,  to  permit  slipping  evenly  into 
the  other.  Both  cylinders  are  well  blackened  inside, 
and  the  larger  is  also  blackened  outside.  The  smaller 
cylinder  is  closed  at  one  end  (concave  surface),  and 
on  its  inner  surface  is  placed  a  colored  lithograph  of 
the  normal  eye  ground.  The  larger  cylinder  is  also 
closed  at  one  end,  except  for  a  central  round  opening 
10  mm.  in  diameter,  which  is  occupied  by  a  +  16  D. 
lens,  and  on  its  outer  surface  is  a  colored  lithograph 
of  the  normal  eye  and  its  appendages  ;  the  pupil 
is  left  dilated,  and  corresponds  to  the  central  open- 


LIGHT-SCREEN   OR   COVER   CHIMNEY.  79 

ing  just  referred  to.  In  addition  to  the  picture  of 
the  eye,  there  is  also  lithographed  on  the  upper  half 
of  the  periphery  the  degree  marks  similar  to  those 
on  a  trial-frame.  To  the  lower  half  of  the  periph- 
ery are  secured,  at  equal  distances,  three  posts 
with  grooves  to  hold  trial-lenses.  On  the  side  of 
the  small  cylinder  is  an  index  which  records  emme- 
tropia,  and  the  amount  of  myopia  and  hyperopia,  as 
it  is  pushed  into  or  drawn  out  of  the  large  cylinder. 
The  eye  is  mounted  on  a  convenient  stand  and  up- 
right, so  that  it  may  be  moved  as  required.  In  using 
this  eye,  if  the  red  eye  ground  and  retinal  vessels 
disturb  the  beginner,  then  he  may  substitute  a  piece 
of  white  paper  for  the  retina.  To  study  astigmatism 
with  the  model,  the  beginner  will  have  to  place  a 
cylinder  of  known  strength  in  the  groove  next  to 
the  eye  and  study  the  characteristic  band  of  light 
so  diagnostic  of  this  condition,  and  at  the  same  time 
he  should  learn  to  locate  the  axis  of  the  band  with 
the  axonometer. 

The  author's  light-screen  or  cover  chimney 
(see  figure  3  and  the  Annals  of  Ophthalmology  and 
Otology,  October,  1896)  is  made  of  one-eighth  inch 
asbestos,  and  of  sufficient  size  to  fit  easily  over  the 
glass  chimney  of  the  Argand  burner;  attached  to 
the  asbestos  by  means  of  a  metal  clamp  are  two 
superimposed  discs,  which  revolve  independently  of 
each  other.  The  lower  disc  contains  a  piece  of  white 
porcelain,  30  mm.  in  diameter ;  also  four  round  open- 
ings, respectively  5,  10,  20,  and  35  mm.  in  diameter. 
The  upper  disc  contains  a  round  35  mm.  opening,  a 
round  section  of  blue  cobalt  glass,  a  perforated  disc, 


8o  RETINOSCOPY. 

a  vertical  and  a  horizontal  slit,  each  2^  by  25  mm. 
The  several  uses  of  this  screen  are  as  follows : 

1 .  For  the  ophthalmoscope  a  good  light  is  obtained 
by  superimposing  the  two  35  mm.  openings. 

2.  Combining  the  35  mm.  opening  in  the  upper 
with  either  the  5  or  10  mm.  in  the  lower  disc,  a 
source  of  light  is  produced  for  the  small  retinoscope  ; 
and, 

3.  By  substituting  the  20  mm.  opening,  light  is  had 
for  the  concave  mirror. 

4.  Placing  the  cobalt  glass  over  the  5,  10,  20,  or 
35  mm.  opening,  and  the  chromo-aberration  test  of 
ametropia  is  given. 

5.  To  test  for  astigmatism  at  one    meter   while 
using  the  plane  mirror,  or  for  heterophoria  at  six 
meters,  the  perforated  disc  is  to  be  turned  over  the 
porcelain,  the  latter  producing  a  clear  white  image. 

6.  The  horizontal   slit  placed  over  the  porcelain 
glass,  and  the  operator  may  exercise    the   oblique 
muscles. 

7.  The  vertical  slit  similarly  placed  gives  the  test 
for  paralyzed  muscles. 

Lenses  for  the  Study  of  the  Scissor  Move- 
ment, Conic  Cornea,  and  Spheric  Aberra- 
tion.— (Described  by  the  author  in  the  Journal 
of  the  American  Medical  Association,  December  1 8, 
1897.) 

As  the  scissor  movement,  conic  cornea,  and  spheric 
aberration,  as  recognized  by  the  retinoscope,  are  so 
difficult  of  demonstration,  except  in  the  individual 
patient,  the  writer  has  suggested  and  had  made  three 
lenses  which  will  illustrate  these  conditions  respec- 


SCISSOR  MOVEMENT,  CONIC  CORNEA,  ABERRATION.      81 


tively  when  placed  in  front  of  his  schematic  eye  ; 
and  thus  the  beginner  in  retinoscopy  may  have  the 
opportunity  to  see,  know,  and  study  these  important 
and  interesting  manifestations  (and  at  small  expense) 
before  proceeding  direct  and  in  comparative  igno- 
rance to  his  patient. 

Figure  41  is  a  plano-concave  cylinder  of  two  diop- 
ters, mounted  in  a  cell  of  the  trial-case,  and  to  one- 
half  of  its  plane  surface  is  cemented  (at  the  same 
axis)  a  plano-convex  cylinder  of  four  diopters,  thus 
making  a  combination  lens,  one  half  of  which  is  a 


FIG.  41. 


-2.0) 


FIG.  42.  FIG.  43. 


—  2  D.  and  the  other  half  is  a  +  2  D.  Placing  this 
lens,  with  its  axis  at  180°,  before  the  schematic  eye 
at  emmetropia  (zero),  and  the  observer  at  one  meter 
distance  with  his  plane  mirror,  the  two  light  areas 
characteristic  of  the  scissor  movement,  with  their 
comparatively  straight  edges  and  dark  interspace, 
may  be  seen  approaching  each  other  from  above  and 
below  (and  the  dark  interspace  disappearing)  as  the 
mirror  is  tilted  in  the  vertical  meridian. 

Figure  42  is  a  section  of  thin  plane  glass  mounted 
as  in  figure  41,  and  has  cemented  at  its  center  a 


82  RETINOSCOPY. 

small  plano-convex  sphere  of  three  diopters,  whose 
base  is  about  four  mm.  in  diameter.  Placing  this 
lens  in  front  of  the  schematic  eye  at  emmetropia, 
and  reflecting  the  light  from  the  plane  mirror  at  one 
meter,  there  will  be  seen  in  the  pupillary  area  a 
small  central  illumination,  which  moves  against  or 
opposite  to  the  movement  of  the  mirror,  and  at  the 
same  time  there  will  also  be  seen  a  peripheral  ring 
(at  the  edge  of  the  iris)  which  moves  rapidly  with 
the  movement  of  the  mirror ;  between  these  light 
areas  is  a  shaded  ring  of  feeble  illumination.  This 
is  the  retinoscopic  picture  and  movement  of  the  light 
areas,  so  indicative  of  conic  cornea.  It  is  also  an 
exaggerated  picture  of  negative  aberration. 

Figure  43  is  made  similar  to  figure  42,  except  that 
at  its  center  is  ground  a  —  2  D.  sphere  of  about  four 
mm.  in  diameter.  To  produce  spheric  aberration 
of  the  positive  form,  place  this  lens  in  front  of  the 
schematic  eye  at  emmetropia,  and  the  observer, 
seated  at  one  meter  distance  with  the  plane  mirror, 
will  see  in  the  pupillary  area  a  central  illumination 
which  moves  slower  than  the  peripheral  area  or 
ring  (at  the  edge  of  the  iris),  which  moves  rapidly, 
both  areas  moving  with  the  movement  of  the  mirror. 

After  the  observer  has  carefully  studied  these  pic- 
tures, it  will  be  obvious  that  changes  other  than  those 
mentioned  can  be  made  with  these  lenses,  and  he 
should  proceed  to  note  them  by — 

1.  Changing  the  focus  of  the  schematic  eye. 

2.  By  varying  his  distance  from  the  eye. 

3.  By  placing  both  the  concave  and  convex  spheres 
in  combination. 


SCISSOR  MOVEMENT,  CONIC  CORNEA,  ABERRATION.      83 

4.  By  placing  a  concave  cylinder  in  front  of  the 
double  cylinder  at  an  oblique  axis,  thus  getting  a 
picture  of  compound  irregular  astigmatism. 

5.  By  placing  a  concave  cylinder  in  front  of  the 
convex  sphere  and  developing  astigmatism  with  the 
conic  cornea,  which  is  the  usual  condition  ;  or  a  con- 
vex cylinder  might  be  used  in  place  of  the  concave 
cylinder  if  a  higher  error  is  desired. 

6.  It  is  obvious,  also,  that  the  scissor  movement 
can  be  produced  by  a  prism  which  is  made  to  cover 
one-half  of  the   pupillary  area,   but   the   resulting 
picture  is  not  so  satisfactory  for  demonstration  as 
that  given  by  the  combination  lens  referred  to  in 
figure  41. 


INDEX. 


ABERRATION,  75,  76 
Accommodation,  28,  29 
Accuracy,  23 
Advantages  of,  20,  21 
Albino,  37 
Amblyopia,  21 
Aphakia,  21,  73 
Apparatus,  47,  48,  65,  66,  67 
Argand  burner,  26 
Arrangement,  32,  33,  34 
Astigmatism,  59,  60 
Avoid,  what  to,  43,  44 
Axiom,  21 
Axonometer,  65 


BAND  of  light,  6l,  62,  63 
Beginner,  23 
Brunette,  37 


CATOPTRIC  images,  44 
Central  shadow,  24,  25,  29 
Compound  irregular  astigmatism,  73, 

74 

Concave  mirror,  28,  78 
Conic  cornea,  74,  75,  8l,  82 
Conjugate  focus,  23,  40 
Cover  chimney,  26,  27 
Cycloplegic,  29 


DARK  room,  27,  28 

Definition,  19 

Dioptroscopy,  19 

Direction  of  movement,  41,  42,  44, 

45.  59 

Discs,  47,  48,  49,  50 
Distance,  31 


EMMETROPIA,  54 

Examples,  41,  59,  60 


FACIAL  illumination,  41 

Fantoscopy,  19 

Far-point,  40 

Form  of  retinal  illumination,  45,  46 

Fundus-reflex  test,  19 


GENERAL  appearances,  36,  37 


HOW  to  use  the  mirror,  34,  35 
Hyperopia,  51,  52,  53,  54 


ILLITERATES,  21 

Illuminated  area,  38 

Illumination,  facial,  41 

retinal,  41,51,  54,  55 

Illustrations,  22,  25,  26,  27,  32,  33, 
34,  35,  38,  46,  47,  48,  51,  52,  53, 
54,  55,  56,  57,  60,  61,62,  63,  66, 
69,  70,  71,  72,  73,  75,  76,  81 

Image,  38 

Images,  44 

Irregular  astigmatism,  68,  69 


JACKSON,  24 

Jennings,  48 


KERATOSCOPY,  19 

Koroscopy,  19 


LENSES,  80,  81,  82 
Lenticular  astigmatism,  69 
Light,  25,  26,  33 
Light-screen,  26,  27,  79,  80 


MACULA,  30,  55 
Meter  distance,  31.  32,  33 


86 


INDEX. 


Mirror,  24,  25,  34,  35 
Mixed  astigmatism,  63,  64 
Movement  of  light,  41,  46,  47 

mirror,  46,  47 
Mulatto,  37 
Myopia,  55,  56,  57 


NAME,  17,  19 
Negative  aberration,  76,  77 
Neutralizing  lenses,  58,  59 
Nystagmus,  21 


OBSERVER,  28,  29,  33 
Oliver,  19 


PATIENT,  29,  30,  33 

Point  of  reversal,  40,  41,  42,  53,  56, 

57 
to  find,  40,  41 

Position  of  light,  32,  33,  34 

mirror,  32,  33,  34 
observer,  32,  33,  34 
patient,  32,  33,  34 

Positive  aberration,  76,  77 

Principle  of  retinoscopy,  20 

Punctum  remotum,  57 

Pupillary  area,  36,  39 

Pupilloscopy,  19 


RATE  of  movement,  44,  45 

Reflection  from  lenses,  44 
mirror,  34 

Regular  astigmatism,  59>  60 

Retinal  illumination,  37,  38 

Retinophotoscopy,  19 

Retinoscope,  24,  25 

Retinoscopy,  19 

advantages  of,  21 
without   a   cycloplegic, 
77 


Retinoskiascopy,  19 
Reversal  of  movement,  56,  57 
Room,  27,  28 
Rules  for  distance,  58,  59 
lenses,  46,  58,  59 


SCHEMATIC  eye,  22,  78,  79 
Scissor  movement,  70,  71,  72,  73,  80, 

81,82 
Shade,  26 
Shadow,  38 

test,  38 
Sight-hole,  24 

Size  of  mirror,  24,  25,  34,  35 
Skiascopy,  19 
Source  of  light,  28 
Spheric  aberration,  75,  76,  80,  81,82 
Squint,  30 
Suggestions  to  the  beginner,  23 


THORINGTON,  22,  25,  26,  27, 

65,  79,  80 
Trial- frame,  50 

UMBRASCOPY,  19 


VALUE  of  retinoscopy,  20 
Vision  of  observer,  29 


WELSBACH,  25 
What  the  observer  sees,  36 

to  avoid,  43,  44 
Where  to  look  and  what  to  look  for, 

39 
Wiirdemann,  47 


YOUNG  children,  21,  33,  67 


Catalogue  No.  8.  April,  1899. 

CLASSIFIED  SUBJECT 
CATALOGUE 

OF 

MEDICAL  BOOKS 

AND 

Books  on  Medicine,  Dentistry,  Pharmacy, 
Chemistry,  Hygiene,  Etc.,  Etc., 

PUBLISHED  BY 

P.  BLAKISTON'S    SON   &   CO., 

Medical  Publishers  and  Booksellers, 

1012  WALNUT  STREET,  PHILADELPHIA. 


SPECIAL  NOTE. — The  prices  given  in  this  catalogue  are 
absolutely  net,  no  discount  will  be  allowed  retail  purchasers 
under  any  consideration.  This  rule  has  been  established  in 
order  that  everyone  will  be  treated  alike,  a  general  reduction 
in  former  prices  having  been  made  to  meet  previous  retail  dis- 
counts. Upon  receipt  of  the  advertised  price  any  book  will 
be  forwarded  by  mail  or  express,  all  charges  prepaid. 

We  keep  a  large  stock  of  Miscellaneous  Books,  not  on  this 
catalogue,  relating  to  Medicine  and  Allied  Sciences,  pub- 
lished in  this  country  and  abroad.  Inquiries  in  regard  to 
prices,  date  of  edition,  etc.,  will  receive  prompt  attention. 

Special  Catalogues  of  Books  on  Pharmacy,  Dentistry, 
Chemistry,  Hygiene,  and  Nursing  will  be  sent  free  upon 
application. 

49- SEE  NEXT  PAGE  FOR  SUBJECT  INDEX. 
Gonld's  Dictionaries,  Page  8. 


SUBJECT   INDEX. 


99~  Any  book*  not  on  this  Catalogue  we  will  furnish  a  price 
for  upon  application. 


SUBJECT.  PAGE 

Alimentary  Canal  (see  Surgeryj  19 

Anatomy 3 

Anesthetics 3 

Autopsies  (sec  Pathology) 16 

Bacteriology  (see  Pathology)  .  16 

Bandaging  (see  Surgery) 19 

Brain  4 

Chemistry 4 

Children,  Diseases  of 6 

Clinical  Charts 6 

Compends aa,  23 

Consumption  (see  Lungs) la 

Dentistry 7 

Diagnosis 17 

Diagrams  (see  Anatomy,  page 
3,  and  Obstetrics,  page  16). 

Dictionaries 8 

Diet  and  Food  (see  Miscella- 
neous)    14 

Dissectors 3 

Domestic  Medicine 10 

Ear 8 

Electricity  9 

Emergencies  (see  Surgery) 19 

Ey« 9 

Fevers 9 

Gout  10 

Gynecoloify  at 

Hay  Fever _ 20 

Heart 10 

Histology 10 

Hospitals  (see  Hygiene) n 

Hygiene n 

Insanity  4 

Latin,  Medical  (see  Miscella- 
neous and  Pharmacy) 14, 16 

Lungs la 

Massage 12 

Materia  Medica 12 

Medical  Jurisprudence 13 

Microscopy  13 

Milk  Analysis  (see  Chemistry)      4 

Miscellaneous  14 

Nervous  Diseases  14 


SUBJECT.  PAGE 

None  ....................................  20 

Nursing  ...............................  15 

Obstetrics  ............................  16 

Ophthalmology  .....................     9 

Osteology  (see  Anatomy)  .......     3 

Pathology  ...........................  16 

Pharmacy  ...........................  16 

Physical  Diagnosis  ...............  17 

Physical  Training  (see  Miscel- 

laneous)  ...........................   14 

Physiology  ..........................  18 

Poisons  (see  Toxicology}  .......  13 

Popular  Medicine  ..................  10 

Practice  of  Medicine  .............  18 

Prescription  Books  ................  18 

Railroad  Injuries  (see  Nervous 

Diseases)  ...........................  14 

Refraction  (see  Eye)  .............    9 

Rheumatism  ........................  10 

Sanitary  Science  ...................  II 

Skin  ....................................  19 

Spectacles  (see  Eye)  ............    9 

Spine  (see  Nervous  Diseases)  14 
Stomach  (see  Miscellaneous)...  14 
Students'  Compends  ..........  22,  8 

Surgery    and     Surgical     Dis- 


Syphilis 

Technological  Books 

Temperature  Charts 

Therapeutics 

Throat  

Toxicology 

Tumors  (see  Surgery) 

U.  S.  Pharmacopoeia 

Urinary  Organs 

Urine. 


'9 


Venereal  Diseases 

Veterinary  Medicine 

Visiting  Lists,  Physicians'. 
(Send  for  SfeciaJ  Circular.) 

Water  Analysis  (see  Chemis- 
try)  

Women,  Diseases  oi 


TTie  prices  as  given  in  this  Catalogue  are  net.  Cloth 
binding,  unless  otherwise  specified.  No  discount  can  be 
allowed  under  any  circumstances.  Any  book  will  be  sent, 
postpaid,  upon  receipt  of  advertised  price. 


SUBJECT  CATALOGUE  OF  MEDICAL  BOOKS.          » 

49*  -All  books  are  bound  in  cloth,  unless  otherwise  speci- 
fied. All  prices  are  net. 

ANATOMY. 

MORRIS.  Text-Book  pt  Anatomy.  2d  Edition.  Revised  and 
Enlarged.  790  Illustrations,  214  ot  which  are  printed  in  colon. 
Just  Ready.  Cloth,  $6.00;  Leather,  $7.00;  Half  Russia,  >8.oo 

"  Taken  as  a  whole,  we  have  no  hesitation  in  according  very  high 
praise  to  this  work.  It  will  rank,  we  believe,  with  the  leading  Anato- 
mies. The  illustrations  are  handsome  and  the  printing  is  good." — 
Boston  Medical  and  Surgical  Journal. 

Handsome  Circular  of  Morris,  with  sample  pages  and  colored  illus- 
trations, will  be  sent  free  to  any  address. 

BROOM  ELL.  Anatomy  and  Histology  of  the  Human  Mouth 
and  Teeth.  284  Illustrations.  Just  Ready.  $4  50 

CAMPBELL.    Outlines  for  Dissection.    Prepared  for  Use  with 
"  Morris's  Anatomy"  by  the  Demonstrator  of  Anatomy  at  the  Uni- 
versity of  Michigan.  •  $1.00 
GORDINIER.     Anatomy  of  the  Central   Nervous  System. 
With    many    Illustrations,    the    majority    of    which    are    original. 
Nearly  Ready.                                                 Cloth,  $6.00;  Sheep,  $7  oo 
HEATH.    Practical  Anatomy.    8th  Edition.    300  Illus.          $4.25 
HOLDEN.     Anatomy.     A  Manual  of  the  Dissections  of  the  Human 
Body.     Carefully  Revised  by  A.  HBWSON,  M.D.,  Demonstrator  of 
Anatomy,  Jefferson  Medical  College,  Philadelphia.  311  Illustrations. 
7th  Edition.     /«  Press. 

HOLDEN.     Human  Osteology.    Comprising  a  Description  of  the 
Bones,  with  Colored  Delineations  of  the  Attachments  of  the  Muscles. 
The  General  and  Microscopical  Structure  of  Bone  and  its  Develop- 
ment.  With  Lithographic  Plates  and  numerous  Illus.   8th  Ed.    $5.25 
HOLDEN.     Landmarks.    Medical  and  Surgical.    4th  Ed.       fi.oo 
MACALISTER.  Human  Anatomy.    Systematic  and  Topograph- 
ical, including  the  Embryology,  H istology ,  and  Morphology  of  Man. 
With  Special  Reference  to  the  Requirements  of  Practical  Surgery  and 
Medicine.    816  Illustrations.  Cloth,  $5.00;  Leather,  $6.00 

MARSHALL.  Physiological  Diagrams.  Life  Size,  Colored. 
Eleven  Life-Size  Diagrams  (each  seven  feet  by  three  feet  seven 
inches).  Designed  for  Demonstration  before  the  Class. 

In  Sheets,  Unmounted,  $40.00;  Backed  with  Muslin  and  Mounted 

on  Rollers,  joo.oo ;  Ditto,  Spring  Rollers,  in  Handsome  Walnut  Wall 

Map  Case,  £100.00;    Single  Plates — Sheets.  $5.00;   Mounted,  $7.50. 

Explanatory  Key,  .50.     Descriptive  circular  upon  application. 

POTTER.    Compend  of  Anatomy,  Including  Visceral  Anatomy. 

6th  Ed.    16  Lith.  Plates  and  117  other  Illus.     .80;  Interleaved,  $1.25 

WILSON.     Human  Anatomy,     nth  Edition.   429  Illustrations,  26 

Colored  Plates,  and  a  Glossary  of  Terms.  ?5-oo 

WINDLE.     Surface  Anatomy  and  Landmarks.     Colored  and 

other  Illustrations.  |i.oo 

ANESTHETICS. 

BUXTON.     On  Anesthetics.     3d  Edition.     Illustrated.  In  Press. 

TURNBULL.  Artificial  Anesthesia.  Anesthetic  Agents  Em- 
ployed in  the  Treatment  of  Disease;  Modes  of  Administration; 
Relative  Risks ;  Tests  of  Purity  ;  Treatment  of  Asphyxia ;  Spasms 
of  the  Glottis ;  Syncope,  etc.  4th  Edition,  Revised.  54  Illus.  $2.50 


SUBJECT  CATALOGUE. 


BRAIN  AND  INSANITY. 

BLACKBURN.  A  Manual  oi  Autopsies.  Designed  for  the  Use 
of  Hospitals  for  the  Insane  and  other  Public  Institutions.  Ten  full- 
page  Plates  and  other  Illustrations.  |i->5 

COWERS.  Diagnosis  of  Diseases  of  the  Brain,  ad  Edition. 
Illustrated.  I'  -5° 

HORSLEY.  The  Brain  and  Spinal  Cord.  The  Structure  and 
Functions  of.  Numerous  Illustrations. 


LEWIS  (BEVAN).  Mental  Diseases.  A  Text-  Book  Having 
Special  Reference  to  the  Pathological  Aspects  ot  Insanity.  18  Litho- 
graphic Plates  and  other  Illustrations.  New  Edition.  Nearly  Ready. 

MANN.  Manual  of  Psychological  Medicine  and  Allied 
Nervous  Diseases.  Their  Diagnosis,  Pathology,  Prognosis,  and 
Treatment,  including  their  Medico-Legal  Aspects  ;  with  chapter  on 
Expert  Testimony,  and  an  Abstract  of  the  Laws  Relating  to  the 
Insane  in  all  the  States  of  the  Union.  Illustrated.  $3-°° 

REGIS.  Mental  Medicine.  Authorized  Translation  by  H.  M. 
BANNISTER,  M.D.  (2.00 

STEARNS.  Mental  Diseases.  Designed  especially  for  Medical 
Students  and  General  Practitioners.  With  a  Digest  of  Laws  of  the 
various  States  Relating  to  Care  of  Insane.  Illustrated. 

Cloth,  $2.75;  Sheep,  £3.  as 

TUKE.  Dictionary  of  Psychological  Medicine.  Giving  the 
Definition,  Etymology,  and  Symptoms  of  the  Terms  used  in  Medical 
Psychology,  with  the  Symptoms,  Pathology,  and  Treatment  of  the 
Recognized  Forms  of  Mental  Disorders,  together  with  the  Law  of 
Lunacy  in  Great  Britain  and  Ireland.  Two  volumes.  £10.00 

WOOD,  H.  C.    Brain  and  Overwork.  .40 

CHEMISTRY  AND  TECHNOLOGY. 

Special  Catalogue  of  Chemical  Books  tent  fret  upon  application. 
ALLEN.  Commercial  Organic  Analysis.  A  Treatise  on  the 
Modes  of  Assaying  the  Various  Organic  Chemicals  and  Products 
Employed  in  the  Arts,  Manufactures,  Medicine,  etc.,  with  concise 
methods  for  the  Detection  of  Impurities,  Adulterations,  etc  8vo. 
Vol.  I.  Alcohols,  Neutral  Alcoholic  Derivatives,  etc  ,  Ethers,  Veg- 

etable Acids,  Starch,  Sugars,  etc.     $d  Edition,  by  HENRY  LBPP- 

MANN,  M.  D.    Just  Ready.  £4.50 

Vol.  II,  Part  I.     Fixed  Oils  and  Fats,  Glycerol,  Explosives,  etc. 

3d  Edition,  by  HENRY  LBFPMANN,  M.  D.    Just  Ready.  $3  50 

Vol.  II,  Part  II.      Hydrocarbons,  Mineral  Oils,  Phenols,  etc.     3d 

Edition,  by  HENRY  LEFFMANN,  M.D.  /*  Press. 

Vol.  Ill,  Part  I.     Acid   Derivatives  of  Phenols,  Aromatic   Acids, 

Tannins,  Dyes  and  Coloring  Matters.  3d  Edition.    In  Preparation. 
Vol.    Ill,    Part    II.      The    Amines,    Hydrazines    and    Derivatives, 

Pyridine  Bases.    The  Antipyretics,  etc.    Vegetable  Alkaloids,  Tea, 

Coffee,  Cocoa,  etc.    8vo.    ad  Edition.  $4-5° 

Vol.  Ill,  Part  III.    Vegetable  Alkaloids,  Non-Basic  Vegetable  bitter 

Principles.    Animal  Bases,  Animal  Acids,  Cyanogen  Compounds, 

etc.    zd  Edition,  8vp.  £*-5° 

Vol.  IV.     The  Proteids  and  Albuminous  Principles,     ad  Edition. 

Just  Ready.  £4.  50 

APPENDIX  VOLUME.    Containing  a  Review  of  the  whole  work  with 

many  new  methods,  etc.  In  Preparation. 

ALLEN.    Chemical  Analysis   of   Albuminous   and    Diabetic 

Urine.    Illustrated.  fa.  25 


MEDICAL  BOOKS. 


HARTLEY.  Medical  and  Pharmaceutical  Chemistry.  A 
Text-Book  for  Medical,  Dental,  and  Pharmaceutical  Students.  With 
Illustrations,  Glossary,  and  Complete  Index.  $th  Edition,  carefully 
Revised.  Just  Ready.  Cloth,  $3.00 ;  Sheep,  $3.50 

BARTLEY.  Clinical  Chemistry.  The  Examination  of  Feces, 
Saliva,  Gastric  Juice,  Milk,  and  Urine.  Just  Ready.  Ji.oo 

BLOXAM.  Chemistry,  Inorganic  and  Organic.  With  Experi- 
ments. 8th  Ed.,  Revised.  281  Engravings.  Clo.,  $4.25  ;  Lea.,  $5.25 

CALDWELL.  Elements  of  Qualitative  and  Quantitative 
Chemical  Analysis.  3<i  Edition,  Revised.  $1-50 

CAMERON.    Oils  and  Varnishes.    With  Illustrations.          $2.25 

CAMERON.     Soap  and  Candles.    54  Illustrations.  $2.00 

GARDNER.  The  Brewer,  Distiller,  and  Wine  Manufac- 
turer. Illustrated.  >I-5° 

GARDNER.    Bleaching,  Dyeing,  and  Calico  Printing.       $1.50 

GROVES  AND  THORP.    Chemical  Technology.    The  Appli- 
cation of   Chemistry  to  the   Arts  and   Manufactures. 
Vol.  I.  Fuel  and  Its  Applications.     607  Illustrations  and  4  Plates. 
Cloth,  $5.00;  Half  Morocco,  $6. 50 

Vol.11.   Lighting.     Illustrated.     Cloth,  $4.00;  Half  Morocco,  $5.50 
Vol.  III.  Lighting — Continued.  In  Press. 

HOLLAND.  The  Urine,  the  Gastric  Contents,  the  Common 
Poisons,  and  the  Milk.  Memoranda,  Chemical  and  Microscopi- 
cal, for  Laboratory  Use.  sth  Ed.  Illustrated  and  interleaved,  Jti. oo 

LEFFMANN.  Compend  of  Medical  Chemistry,  Inorganic 
and  Organic.  Including  Urine  Analysis.  4th  Edition,  Rewritten 
and  Revised.  .80  ;  Interleaved,  $1.25 

LEFFMANN.  Analysis  of  Milk  and  Milk  Products.  Arranged 
to  Suit  the  Needs  of  Analytical  Chemists,  Dairymen,  and  Milk  Inspec- 
tors. 2d  Edition.  Enlarged,  Illustrated.  $1.25 

LEFFMANN.     Water  Analysis.     Illustrated,    sd  Edition.    $1.25 

LEFFMANN.  Structural  Formula.  Including  180  Structural 
and  Stereo-Chemical  Formulae.  lamo.  Interleaved.  Ji.oo 

LEFFMANN  AND  BEAM.  Select  Methods  in  Food  An- 
alysis. In  Preparation. 

MUTER.  Practical  and  Analytical  Chemistry.  26  American 
from  the  Eighth  English  Edition.  Revised  to  meet  the  requirements 
of  American  Medical  Colleges  by  CLAUDE  C.  HAMILTON,  M.D.  56 
Illustrations.  Just  Ready.  ^I>25 

OETTEL.  Practical  Exercises  in  Electro-Chemistry.  Illus- 
trated. .75 

OETTEL.  Introduction  to  Electro-Chemical  Experiments. 
Illustrated.  .75 

RICHTER.  Inorganic  Chemistry.  4th  American,  from  6th  Ger- 
man Edition.  Authorized  translation  by  EDGAR  F.  SMITH,  M.A., 
PH.D.  89  Illustrations  and  a  Colored  Plate.  $I-75 

RICHTER.  Organic  Chemistry.  3d  American  Edition.  Trans, 
from  the  last  German  by  EDGAR  F.  SMITH.  Illustrated.  2  Volumes. 
Vol.  I.  Aliphatic  Series.  625  Pages.  Just  Ready.  $3-°° 

Vol.  II.  Aromatic  Series.  In  Preparation. 

SMITH.  Electro-Chemical  Analysis.  2d  Edition,  Revised.  28 
Illustrations.  tT-25 

SMITH  AND  KELLER.  Experiments.  Arranged  for  Students 
in  General  Chemistry.  3d  Edition.  Illustrated.  .60 


SUBJECT  CATALOGUE. 


STAMMER.  Chemical  Problems.  With  Answers.  .50 

BUTTON.  Volumetric  Analysis.  A  Systematic  Handbook  for 

the  Quantitative  Estimation  of  Chemical  Substances  by   Measure, 

Applied  to  Liquids,  Solids,  and  Gases.      7th  Edition,  Revised,     na 

Illustrations.  £4.50 

SYMONDS.  Manual  of  Chemistry,  for  Medical  Students. 

ad  Edition.  $a.oo 

TRAUBE.  Physico-Chemical  Methods.  Translated  by  Hardin. 

97  Illustrations.  Just  Ready.  $1.50 

ULZER  AND  FRAENKEL.  Chemical  Technical  Analysis. 

Translated  by  Heck.  Illustrated.  Jutt  Ready.  .  $1.35 

WOODY.  Essentials  of  Chemistry  and  Urinalysis.  4th 

Edition.    Illustrated.  In  Prtts. 

S*  Special  Cataloptt  of  Books  OH  Ckemittry  frtt  upon  application. 

CHILDREN. 

CAUTLIE.    Feeding  of  Infants  and  Young  Children  by  Nat- 
ural and  Artificial  Methods.  $2.00 
HALE.    On  the  Management  of  Children.  .50 

HATPIELD.  Compend  of  Diseases  of  Children.  With  a 
Colored  Plate,  ad  Edition.  .80;  Interleaved,  f  1.25 

MEIQS.  Infant  Feeding  and  Milk  Analysis.  The  Examination 
of  Human  and  Cow's  Milk,  Cream,  Condensed  Milk,  etc.,  and 
Directions  as  to  the  Diet  of  Young  Infants.  .50 

MONEY.  Treatment  of  Diseases  in  Children.  Including  the 
Outlines  of  Diagnosis,  ad  Edition.  >J-5° 

POWER.  Surgical  Diseases  of  Children  and  their  Treat- 
ment by  Modern  Methods.  Illustrated.  t*-So 

STARR.  The  Digestive  Organs  in  Childhood.  The  Diseases  oi 
the  Digestive  Organs  in  Infancy  and  Childhood.  With  Chapters  on 
the  Investigation  of  Disease  and  the  Management  of  Children,  ad 
Edition,  Enlarged.  Illustrated  by  two  Colored  Plates  and  numerous 
Wood  Engravings.  fa.oo 

STARR.  Hygiene  of  the  Nursery.  Including  the  General  Regi- 
men and  Feeding  of  Infants  and  Children,  and  the  Domestic  Manage- 
ment of  the  Ordinary  Emergencies  of  Early  Life,  Massage,  etc.  6th 
Edition.  25  Illustrations.  fi.oo 

TAYLOR  AND  WELLS.  The  Diseases  of  Children.  Illus- 
trated. A  New  Manual.  746  pages.  Jutt  Ready.  $4.00 

CLINICAL  CHARTS. 

GRIFFITH.  Graphic  Clinical  Chart  for  Recording  Temper- 
ature, Respiration,  Pulse,  Day  of  Disease,  Date,  Age,  Sex, 
Occupation,  Name,  etc.  Printed  in  three  colors.  Sample  copies 
free.  Put  up  in  loose  packages  of  fifty,. 50.  Price  to  Hospitals,  500 
copies,  $4.00;  looo  copies,  17.50.  With  name  of  Hospital  printed 
on,  .50  extra. 

KEEN'S  CLINICAL  CHARTS.  Seven  Outline  Drawings  of  the 
Body,  on  which  may  be  marked  the  Course  of  Disease,  Fractures, 
Operations,  etc.  Pads  of  fifty,  fi.co.  Each  Drawing  may  also  be 
had  separately,  twenty-five  to  pad,  25  cents. 


MEDICAL  BOOKS. 


SCHREINER.  Diet  Lists.  Arranged  in  the  form  of  a  chart. 
With  Pamphlets  of  Specimen  Dietaries.  Pads  of  50.  .75 

DENTISTRY. 

Special  Catalogue  of  Dental  Books  sent  free  upon  application. 

BARRETT.  Dental  Surgery  for  General  Practitioners  and 
Students  of  Medicine  and  Dentistry.  Extraction  of  Teeth, 
etc.  3d  Edition.  Illustrated.  Nearly  Ready. 

BLODGETT.  Dental  Pathology.  By  ALBERT  N.  BLODGBTT, 
M  D.,  late  Professor  of  Pathology  and  Therapeutics,  Boston  Dental 
College.  33  Illustrations.  tt-*S 

BROOMELL.  Anatomy  and  Histology  of  the  Human  Mouth 
and  Teeth.  284  Handsome  Illustrations.  Just  Ready.  $4.50 

FLAGG.  Plastics  and  Plastic  Filling,  as  Pertaining  to  the  Filling 
of  Cavities  in  Teeth  of  all  Grades  of  Structure.  4th  Edition.  $4.00 

FILLEBROWN.  A  Text-Book  of  Operative  Dentistry. 
Written  by  invitation  of  the  National  Association  of  Dental  Facul- 
ties. Illustrated.  $2-25 

GORGAS.  Dental  Medicine.  A  Manual  of  Materia  Medica  and 
Therapeutics.  6th  Edition,  Revised.  Cloth,  $4.00;  Sheep,  $5.00 

HARRIS.  Principles  and  Practice  of  Dentistry.  Including 
Anatomy,  Physiology,  Pathology,  Therapeutics,  Dental  Surgery, 
and  Mechanism.  i3th  Edition.  Revised  by  F.  J.  S.  GORGAS,  M.D., 
D.D.S.  1250  Illustrations.  Cloth,  $6.00;  Leather,  $7.00 

HARRIS.  Dictionary  of  Dentistry.  Including  Definitions  of  Such 
Words  and  Phrases  of  the  Collateral  Sciences  as  Pertain  to  the  Art  and 
Practice  of  Dentistry.  6th  Edition.  Revised  and  Enlarged  by  FER- 
DINAND F.  S.  GORGAS,  M.D.,  D.D.S.  Cloth,  $5.00;  Leather,  $6.00 

HEATH.    Injuries  and  Diseases  of  the  Jaws.  4th  Edition.  187 

Illustrations.  ?4-5o 

HEATH.    Lectures  on  Certain   Diseases  of  the  Jaws.     64 

Illustrations.  Boards,  .50 

RICHARDSON.  Mechanical  Dentistry.  7th  Edition.  Thor- 
oughly Revised  and  Enlarged  by  DR.  GEO.  W.  WARRBN.  691  Illus- 
trations. Cloth,  $5.00;  Leather,  J6. oo 

SEWELL.  Dental  Surgery.  Including  Special  Anatomy  and 
Surgery.  3d  Edition,  with  200  Illustrations.  $2.00 

SMITH.     Dental  Metallurgy.    Illustrated.  $1.75 

TAFT.    Index  of  Dental  Periodical  Literature.  $2.00 

TALBOT.  Irregularities  of  the  Teeth  and  Their  Treatment. 
2d  Edition.  234  Illustrations.  $3-oo 

TOMES.  Dental  Anatomy.  Human  and  Comparative.  263  Illus- 
trations, sth  Edition.  Just  Ready.  $4.00 

TOMES.     Dental  Surgery.    4th  Edition.     289  Illustrations.     $4.00 

WARREN.    Compend  of  Dental  Pathology  and  Dental  Medi- 
cine.    With  a  Chapter  on  Emergencies.     3d  Edition.     Illustrated. 
Just  Ready.  .80;  Interleaved,  $1.25 

WARREN.  Dental  Prosthesis  and  Metallurgy.  129  Ills.  $1.25 
WHITE.     The  Mouth  and  Teeth.     Illustrated.  .40 

***  Special  Catalogue  of  Dental  Books  free  upon  application. 


SUBJECT  CATALOGUE. 


DICTIONARIES. 

GOULD.    The  Illustrated   Dictionary  of  Medicine,  Biology, 
and  Allied  Science*.    Being  an  Exhaustive  Lexicon  of  Medicine 
and  those  Sciences  Collateral  to  it:    Biology  (Zoology  and  Botany), 
Chemistry,   Dentistry,  Parmacology,  Microscopy,  etc.,  with  many 
useful  Tables  and  numerous  fine  Illustrations.     1633  PaKes-    4tn  Ed- 
Sheep  or  Half  Dark  Green  Leather,  $10.00;  Thumb  Index,  f 11.00 
Half  Russia,  Thumb  Index,  f 12.00 

GOULD.  The  Medical  Student's  Dictionary.  Including  all  the 
Words  and  Phrases  Generally  Used  in  Medicine,  with  their  Proper 
Pronunciation  and  Definition,  Based  on  Recent  Medical  Literature. 
With  Tables  of  the  Bacilli,  Micrococci,  Mineral  Springs,  etc.,  of  the 
Arteries,  Muscles,  Nerves, Ganglia,  and  Plexuses,  etc.  loth  Edition. 
Rewritten  and  Enlarged.  Completely  reset  from  new  type.  700  pp. 
Half  Dark  Leather,  $3.25  ;  Half  Morocco,  Thumb  Index,  £4.00 

GOULD.  The  Pocket  Pronouncing  Medical  Lexicon.  (21,000 
Medical  Words  Pronounced  and  Defined.)  Containing  all  the  Words, 
their  Definition  and  Pronunciation,  that  the  Medical,  Dental,  or 
Pharmaceutical  Student  Generally  Comes  in  Contact  With;  also 
Elaborate  Tables  of  the  Arteries,  Muscles.  Nerves,  Bacilli,  etc.,  etc., 
a  Dose  List  in  both  English  and  Metric  System,  etc.,  Arranged  in  a 
Most  Convenient  Korm  for  Reference  and  Memorizing.  A  new  Edi- 
tion, enlarged  by  200  pages.  Just  Ready. 

Full  Limp  Leather,  Gilt  Edges,  $1.00 ;  Thumb  Index,  $1.25 
85,000  Copies  of  Gould's  Dictionaries  Have  Been  Sold. 
***  Sample  Pages  and    Illustrations  and    Descriptive   Circulars    ot 

Gould's  Dictionaries  sent  free  upon  application. 

HARRIS.  Dictionary  of  Dentistry.  Including  Definitions  of  Such 
Words  and  Phrases  of  the  Collateral  Sciences  as  Pertain  to  the  Art 
and  Practice  of  Dentistry.  6th  Edition.  Revised  and  Enlarged  by 
FERDINAND  J.  S.  GORGAS,  M.D.,  D.D.S.  Cloth,  $5.00;  Leather,  $6  oo 

LONGLEY.  Pocket  Medical  Dictionary.  With  an  Appendix, 
containing  Poisons  and  their  Antidotes,  Abbreviations  used  in  Pre- 
scriptions, etc.  Cloth,  .75;  Tucks  and  Pocket,  £i .00 

MAXWELL.  Terminologia  Medica  Polyglotta.  By  Dr. 
THBODORB  MAXWELL,  Assisted  by  Others.  $3-°o 

The  object  of  this  work  is  to  assist  the  medical  men  ot  any  nationality 

in   reading   medical  literature   written   in  a  language  not   their  own. 

Each  term  is  usually  given  in  seven  languages,  vii. :  English,  French, 

German,  Italian,  Spanish,  Russian,  and  Latin. 

TREVES  AND  LANG.    German-English  Medical  Dictionary. 

Half  Russia,  $3.25 

EAR  (see  also  Throat  and  Nose). 

BURNETT.    Hearing  and  How  to  Keep  It.    Illustrated.         .40 

DALBY.  Diseases  and  Injuries  of  the  Ear.  4th  Edition.  38 
Wood  Engravings  and  8  Colored  Plates.  t*-S° 

HOVELL.  Diseases  of  the  Ear  and  Naso-Pharynx.  Includ- 
ing Anatomy  and  Physiology  of  the  Organ,  together  with  the  Treat- 
ment of  the  Affections  of  the  Nose  and  Pharynx  which  Conduce  to 
Aural  Disease,  in  Illustrations.  xA  Edition.  Preparing. 

PRITCHARD.  Diseases  of  the  Ear.  3d  Edition,  Enlarged. 
Many  Illustrations  and  Formulae.  $'-5° 

WOAKES.  Deafness,  Giddiness,  and  Noises  in  the  Head. 
4th  Edition.  Illustrated.  $2.00 


MEDICAL  BOOKS. 


ELECTRICITY. 

BIGELOW.  Plain  Talks  on  Medical  Electricity  and  Bat- 
teries. With  a  Therapeutic  Index  and  a  Glossary.  43  Illustra- 
tions, zd  Edition.  £1.00 

JONES.   Medical  Electricity,  ad  Edition.  113  Illus.        hi  Press. 

MASON.  Electricity ;  Its  Medical  and  Surgical  Uses.  Numer- 
ous Illustrations.  .75 

EYE. 

A  Special  Circular  of  Books  on  the  Eye  tent  frte  upon  application. 

ARLT.  Diseases  of  the  Eye.  Clinical  Studies  on  Diseases  of  the 
Eye.  Translation  by  LYMAN  WARE.  M.D.  Illustrated.  t*-3S 

BONDERS.  The  Nature  and  Consequences  of  Anomalies  of 
Refraction.  With  Portrait  and  other  Illustrations.  8vo. 

Half  Morocco,  $1.25 

PICK.  Diseases  of  the  Eye  and  Ophthalmoscopy.  Trans- 
lated by  A.  B.  HALE,  M.  D.  157  Illustrations,  many  of  which  are  in 
colors,  and  a  glossary.  Cloth,  $4.50;  Sheep,  {5.50 

GOULD  AND  PYLE.  Compend  of  Diseases  of  the  Eye  and 
Refraction.  Including  Treatment  and  Operations,  and  a  Section 
on  Local  Therapeutics.  With  Formulae,  Useful  Tables,  a  Glossary, 
and  in  Illustrations,  several  of  which  are  in  colors. 

Cloth,  .80;  Interleaved,  $1.25 

GOWERS.  Medical  Ophthalmoscopy.  A  Manual  and  Atlas 
with  Colored  Autotype  and  Lithographic  Plates  and  Wood-cuts, 
Comprising  Original  Illustrations  of  the  Changes  of  the  Eye  in  Dis- 
eases of  the  Brain,  Kidney,  etc.  3d  Edition.  £4.00 

HARLAN.    Eyesight,  and  How  to  Care  for  It.    Illus.  .40 

HARTRIDGE.  Refraction.  104  Illustrations  and  Test  Types, 
gth  Edition,  Enlarged.  Just  Ready.  Ji-5o 

HARTRIDGE.  On  the  Ophthalmoscope.  3d  Edition.  With 
4  Colored  Plates  and  68  Wood-cuts.  $1-50 

HANSELL  AND  REBER.  Muscular  Anomalies  of  the  Eye. 
Illustrated.  Just  Ready.  >'-5° 

HANSELL  AND  BELL.  Clinical  Ophthalmology.  Colored 
Plate  of  Normal  Fundus  and  120  Illustrations.  $1.50 

JESSOP.  Manual  of  Ophthalmic  Surgery  and  Medicine.  Col- 
ored Plates  and  108  other  Illustrations.  Just  Ready.  Cloth,  $300 

MORTON.  Refraction  of  the  Eye.  Its  Diagnosis  and  the  Cor- 
rection of  its  Errors.  With  Chapter  on  Keratoscopy  and  Test 
Types.  6th  Edition.  |i.oo 

OHLEMANN.  Ocular  Therapeutics.  Authorized  Translation, 
and  Edited  by  DR.  CHARLES  A.  OLIVER.  Just  Ready.  $J-75 

PHILLIPS.  Spectacles  and  Eyeglasses.  Their  Prescription 
and  Adjustment,  ad  Edition.  49  Illustrations.  $1.00 

SWANZY.  Diseases  of  the  Eye  and  Their  Treatment.  6th 
Edition,  Revised  and  Enlarged.  158  Illustrations,  i  Plain  Plate, 
and  a  Zephyr  Test  Card.  $3.00 

THORINGTON.    Retinoscopy.    2d  Edition.     Illustrated.       fi.oo 

WALKER.  Students'  Aid  in  Ophthalmology.  Colored  Plate 
and  40  other  Illustrations  and  Glossary.  £1.50 


10  SUBJECT  CATALOGUE. 

FEVERS. 

COLLIE.  On  Fever*.  Their  History,  Etiology,  Diagnosis,  Prog- 
nosis, and  Treatment.  Colored  Piates.  fz.oo 

QOODALL  AND  WASHBOURN.  Fevers  and  Their  Treat- 
ment. Illustrated.  |3-oo 

GOUT  AND  RHEUMATISM. 

DUCKWORTH.  A  Treatise  on  Gout.  With  Chromo-lithographs 
and  Engravings.  Cloth,  fo.oo 

OARROD.  On  Rheumatism.  A  Treatise  on  Rheumatism  and 
Rheumatic  Arthritis.  Cloth,  $5.00 

HAIO.  Causation  of  Disease  by  Uric  Acid.  A  Contribution  to 
the  Pathology  of  High  Arterial  Tension,  Headache,  Epilepsy,  Gout, 
Rheumatism,  Diabetes,  Bright's  Disease,  etc.  4th  Edition.  $3.00 

HEALTH    AND     DOMESTIC    MEDI- 
CINE (see  also  Hygiene  and  Nursing). 

BUCKLEY.    The  Skin  in  Health  and  Disease,    lllus.  .40 

BURNETT.    Hearing  and  How  to  Keep  It.    Illustrated.  .40 

COHEN.    The  Throat  and  Voice.     Illustrated.  .40 

DULLES.    Emergencies.    4th  Edition.    Illustrated.  fi.oo 
HARLAN.    Eyesight  and  How  to  Care  for  It.    Illustrated.     .40 

HARTSHORNE.    Our  Homes.    Illustrated.  .40 

OSGOOD.    The  Winter  and  its  Dangers.  .40 

PACKARD.    Sea  Air  and  Bathing.  .40 

PARKES.    The  Elements  of  Health.  fi.a5 

RICHARDSON.    Long  Life  and  How  to  Reach  It.  .40 

WESTLAND.    The  Wife  and  Mother.  $1.50 

WHITE.    The  Mouth  and  Teeth.    Illustrated.  .40 

WILSON.    The  Summer  and  its  Diseases.  .40 

WOOD.    Brain  Work  and  Overwork.  .40 

STARR.    Hygiene  of  the  Nursery.    $th  Edition.  $1.00 

CANFIELD.    Hygiene  of  the  Sick-Room.  $1.25 

HEART. 

SANSOM.  Diseases  of  the  Heart.  The  Diagnosis  and  Pathology 
of  Diseases  of  the  Heart  and  Thoracic  Aorta.  With  Plates  and  other 
Illustrations.  $6.00 

HISTOLOGY. 

STIRLING.  Outlines  of  Practical  Histology.  368  Illustrations, 
ad  Edition,  Revised  and  Enlarged.  With  new  Illustrations.  fa.oo 

STOHR.  Histology  and  Microscopical  Anatomy.  Translated 
and  Edited  by  A.  SCHAPBR,  M.D.,  Harvard  Medical  School.  Second 
Edition,  Revised  and  Enlarged.  29*  Illustrations.  >3-°° 


MEDICAL  BOOKS.  11 


HYGIENE  AND  WATER  ANALYSIS. 

Special  Catalogue  of  Books  on  Hygiene  sent  free  upon  application. 

CANFIELD.  Hygiene  of  the  Sick-Room.  A  Book  for  Nurses 
and  Others  Being  a  Brief  Consideration  of  Asepsis,  Antisepsis,  Dis- 
infection, Bacteriology,  Immunity,  Heating  and  Ventilation,  and 
Kindred  Subjects.  $i-*5 

COPLIN  AND  BEVAN.  Practical  Hygiene.  A  Complete 
American  Text-Book.  138  Illustrations.  New  Ed.  Preparing. 

FOX.  Water,  Air,  and  Food.  Sanitary  Examinations  of  Water, 
Air,  and  Food.  100  Engravings,  ad  Edition,  Revised.  $3-5° 

KENWOOD.  Public  Health  Laboratory  Work.  116  Illustra- 
tions and  3  Plates.  $2.00 

LEFFMANN.  Examination  of  Water  for  Sanitary  and 
Technical  Purposes.  3d  Edition.  Illustrated.  t*-25 

LEFFMANN.  Analysis  of  Milk  and  Milk  Products.  Illus- 
trated. $1.25 

LINCOLN.    School  and  Industrial  Hygiene.  .40 

MACDONALD.  Microscopical  Examinations  of  'Water  and 
Air.  25  Lithographic  Plates,  Reference  Tables,  etc.  ad  Ed.  $2.50 

McNEILL.  The  Prevention  of  Epidemics  and  the  Construc- 
tion and  Management  of  Isolation  Hospitals.  Numerous  Plans 
and  Illustrations.  $3-5° 

NOTTER  AND  FIRTH.  The  Theory  and  Practice  of  Hygiene. 
(Being  the  gth  Edition  of  Parkes'  Practical  Hygiene,  rewritten  and 
brought  up  to  date.)  10  Plates  and  135  other  Illustrations.  1034 
pages.  8vo.  t7-°° 

PARKES.  Hygiene  and  Public  Health.  By  Louis  C.  Parkes, 
M.D.  sth  Edition.  Enlarged.  Illustrated.  $2-50 

PARKES.  Popular  Hygiene.  The  Elements  of  Health.  A  Book 
for  Lay  Readers.  Illustrated.  tl-35 

STARR.  The  Hygiene  of  the  Nursery.  Including  the  General 
Regimen  and  Feeding  of  Infants  and  Children,  and  the  Domestic 
Management  of  the  Ordinary  Emergencies  of  Early  Life,  Massage, 
etc.  6th  Edition.  25  Illustrations.  Ji.oo 

STEVENSON  AND  MURPHY.  A  Treatise  on  Hygiene.  By 
Various  Authors.  In  Three  Octave  Volumes.  Illustrated. 

Vol.  I,  $6.00;  Vol.  II,  $6.00;  Vol.  Ill,  $5.00 
%*  Each  Volume  sold  separately.  Special  Circular  upon  application. 

WILSON.  Hand-Book  of  Hygiene  and  Sanitary  Science. 
With  Illustrations.  Sth  Edition.  Just  Ready.  $3-°° 

WEYL.  Sanitary  Relations  of  the  Coal-Tar  Colors.  Author- 
ized Translation  by  HENRY  LEFFMANN,  M.D.,  PH.D.  $I-35 
***  Special  Catalogue  of  Books  on  Hygiene  free  upon  application, 

LUNGS  AND  PLEURAE. 

HARRIS  AND  BEALE.  Treatment  of  Pulmonary  Consump- 
tion. $2.50 

POWELL.  Diseases  of  the  Lungs  and  Pleurae,  including 
Consumption.  Colored  Plates  and  other  Illus.  4th  Ed.  £4.00 

TUSSEY.  High  Altitudes  in  the  Treatment  of  Consumption. 

$1.50 


11  SUBJECT  CATALOGUE. 

MASSAGE. 

KLEEN.  Hand-Book  of  Massage.  Authorized  translation  by 
MUSSBT  HARTWBLL,  M.D.,  PH.D.  With  an  Introduction  by  Dr.  S. 
WHIR  MITCHELL.  Illustrated  by  a  series  ol  Photographs  Made 
Especially  by  DR.  KLHBN  for  the  American  Edition.  £>-*5 

MURRELL.  Massotherapeutics.  Massage  as  a  Mode  of  Treat- 
ment. 6th  Edition.  In  Prtit. 

OSTROM.  Massage  and  the  Original  Swedish  Move- 
ments.  Their  Application  to  Various  Diseases  of  the  Body.  A 
Manual  for  Students,  Nurses,  and  Physicians.  Third  Edition,  En- 
larged. 94  Wood  Engravings,  many  of  which  are  original.  jh.oo 

WARD.     Notes  on  Massage.     Interleaved.          Paper  cover, fi.oo 

MATERIA    MEDICA    AND     THERA- 
PEUTICS. 

ALLEN,  HARLAN,  HARTE,  VAN  HARLINOEN.  A 
Hand-Book  of  Local  Therapeutics,  Beinga  Practical  Description 
of  all  those  Agents  Used  in  the  Local  Treatment  of  Diseases  of  the 
Eye,  Ear,  Nose  and  Throat.  Mouth,  Skin,  Vagina,  Rectum,  etc., 
such  as  Ointments,  Plasters,  Powders,  Lotions,  Inhalations,  Supposi- 
tories, Bougies,  Tampons,  and  the  Proper  Methods  of  Preparing  and 
Applying  Them.  Cloth,  $3.00  ;  Sheep,  £4.00 

BIDDLE.  Materia  Medica  and  Therapeutics.  Including  Dose 
List,  Dietary  for  the  Sick,  Table  of  Parasites,  and  Memoranda  ol 
New  Remedies,  ipth  Edition,  Thoroughly  Revised  in  accord- 
ance with  the  new  U.  S.  P.  64  Illustrations  and  a  Clinical  Index. 

Cloth,  $4.00;  Sheep,  $5.00 

BRACKEN.     Outlines  of  Materia  Medica  and  Pharmacology.    12.75 
COBLENTZ.    The  Newer  Remedies.    3d  Edition,  Enlarged  and 
Revised.  Nearly  Ready. 

DAVIS.    Materia  Medica  and  Prescription  Writing.        fi  .50 
FIELD.     Evacuant  Medication.    Cathartics  and  Emetics.      £1.75 
QOROAS.     Dental  Medicine.    A  Manual  of  Materia  Medica  and 
Therapeutics.    6th  Edition,  Revised.  £4.00 

GROFF.     Materia  Medica  for  Nurses.    Just  Ready.  >'-»5 

HELLER.  Essentials  of  Materia  Medica,  Pharmacy,  and 
Prescription  Writing.  $*-5° 

MAYS.    Theine  in  the  Treatment  of  Neuralgia.     %  bound,  .50 
NAPHEYS.     Modern   Therapeutics,    gth   Revised  Edition,  En- 
larged and  Improved.   In  two  handsome  volumes.     Edited  by  ALLEN 
I.  SMITH,  M.D.,  and  J.  AUBREY  DAVIS,  M.D. 

Vol.  I.  General  Medicine  and  Diseases  of  Children.  |4-oo 

Vol.  II.  General  Surgery,  Obstetrics,  and  Diseases  of  Women.  $4.00 
POTTER.  Hand-Book  of  Materia  Medica,  Pharmacy,  and 
Therapeutics,  including  the  Action  of  Medicines,  Special  Therapeu- 
tics, Pharmacology,  etc.,  including  over  600  Prescriptions  and  For- 
mulae. 7th  Edition.  Revised  and  Enlarged.  With  Thumb  Index  in 
each  copy.  Just  Ready.  Cloth,  fvoo;  Sheep,  £6.co 

POTTER.  Compend  of  Materia  Medica,  Therapeutics,  and 
Prescription  Writing,  with  Special  Reference  to  the  Physiologi- 
cal Action  of  Drugs.  6th  Revised  and  Improved  Edition,  based  upon 
the  U.  S.  P.  1890.  .80;  Interleaved,  fi.as 


MEDICAL  BOOKS.  13 


SAYRE.  Organic  Materia  Medica  and  Pharmacognosy.  An 
Introduction  to  the  Study  of  the  Vegetable  Kingdom  and  the  Vege- 
table and  Animal  Drugs.  Comprising  the  Botanical  and  Physical 
Characteristics.  Source,  Constituents,  and  Pharmacopeial  Prepara- 
tions. With  chapters  on  Synthetic  Organic  Remedies,  Insects  In- 
jurious to  Drugs,  and  Pharmacal  Botany.  A  Glossary  and  543  Illus- 
trations, many  of  which  are  original,  ad  Edition.  Preparing. 

WARING.  Practical  Therapeutics.  4th  Edition,  Revised  and 
Rearranged.  Cloth,  $2.00;  Leather,  $3.00 

WHITE  AND  WILCOX.  Materia  Medica,  Pharmacy,  Phar- 
macology, and  Therapeutics.  4th  American  Edition,  Revised  by 
REYNOLD  W.  WILCOX,  M.A.,  M.D.,  LL.D.  Clo.,  $3.00;  Lea.,  £3.50 


MEDICAL    JURISPRUDENCE     AND 
TOXICOLOGY. 

REESE.  Medical  Jurisprudence  and  Toxicology.  A  Text-Book 
for  Medical  and  Legal  Practitioners  and  Students.  5th  Edition. 
Revised  by  HENRY  LBFFMANN,  M.D.  Clo.,  $3.00  ;  Leather,  $3.50 

"  To  the  student  of  medical  jurisprudence  and  toxicology  it  is  in- 
valuable, as  it  is  concise,  clear,  and  thorough  in  every  respect." — The 
American  Journal  of  the  Medical  Sciences. 

MANN.    Forensic  Medicine  and  Toxicology.    Illus.          $6.50 

MURRELL.      What   to    Do    in    Cases    of  Poisoning.      7th 

Edition,  Enlarged.  £1.00 

TANNER.  Memoranda  of  Poisons.  Their  Antidotes  and  Tests. 
7th  Edition.  .75 

MICROSCOPY. 

BEALE.    The  Use  of  the  Microscope  in  Practical  Medicine. 

For  Students  and  Practitioners, with  Full  Directions  for  Examining  the 
Various  Secretions,  etc.,  by  the  Microscope.  4th  Ed.   500  Illus.  $6.50 

BEALE.  How  to  Work  with  the  Microscope.  A  Complete 
Manual  of  Microscopical  Manipulation,  containing  a  Full  Description 
of  many  New  Processes  of  Investigation,  with  Directions  for  Examin- 
ing Objects  Under  the  Highest  Powers,  and  for  Taking  Photographs 
of  Microscopic  Objects,  sth  Edition.  400  Illustrations,  many  of 
them  colored.  $6-5° 

CARPENTER.  The  Microscope  and  Its  Revelations.  8th 
Edition.  800  Illustrations  and  many  Lithographs.  Preparing. 

LEE.  The  Microtomist's  Vade  Mecum.  A  Hand-Book  of 
Methods  of  Microscopical  Anatomy.  887  Articles.  4th  Edition, 
Enlarged.  t4-°° 

M  ACDONALD.  Microscopical  Examinations  of  Water  and  Air. 
25  Lithographic  Plates,  Reference  Tables,  etc.  2d  Edition.  $2.50 

REEVES.  Medical  Microscopy,  including  Chapters  on  Bacteri- 
ology, Neoplasms,  Urinary  Examination,  etc.  Numerous  Illus- 
trations, some  of  which  are  printed  in  colors.  $2-5° 

WETHERED.  Medical  Microscopy.  A  Guide  to  the  Use  of  the 
Microscope  in  Practical  Medicine.  100  Illustrations.  $2.00 


14  SUBJECT  CATALOGUE. 

MISCELLANEOUS. 

BLACK.  Micro-Organisms.  The  Formation  of  Poisons.  A 
Biological  Study  of  the  Germ  Theory  of  Disease.  .75 

BURNETT.  Poods  and  Dietaries.  A  Manual  of  Clinical  Diet- 
etics.  ad  Edition.  >>-5° 

GOULD.  Borderland  Studies.  Miscellaneous  Addresses  and 
Essays.  1 2  mo.  Ja.oo 

QOWERS.    The  Dynamics  of  Life.  .75 

HAIG.    Causation  of  Disease  by  Uric  Acid.    A  Contribution  to 
the  Pathology  of  High  Arterial  Tension,  Headache,  Epilepsy,  Gout, 
Rheumatism,  Diabetes,  Bright's  Disease,  etc.    4th  Edition.       £3.00 
HAIG.     Diet  and  Food.    Considered  in  Relation  to  Strength  and 
Power  of  Endurance.    Jutt  Ready,  fi.oo 

HARE.     Mediastinal  Disease.    Illustrated  by  six  Plates.       $100 
HEMMETER.     Diseases  of  the  Stomach.    Their  Special  Path- 
ology, Diagnosis,  and  Treatment.     With  Sections  on  Anatomy,  Diet- 
etics, Surgery,  etc.    Illustrated.  Clo.  $6.00;  Sn.  % 7.00 
HENRY.    A  Practical  Treatise  on  Anemia.          Halt  Cloth,  .50 
LEPFMANN.    The  Coal-Tar  Colors.    With  Special  Reference  to 
their  Injurious  Qualities  and  the  Restrictions  of  their  Use.    A  Trans- 
lation of  THEODORE  WKYL'S  Monograph.  $1.25 
MARSHALL.    History  of  Woman's  Medical  College  of  Penn- 
sylvania. fi-5° 
NEW  SYDENHAM  SOCIETY'S  PUBLICATIONS.    Circulars 
upon  application.                                                              Per  Annum,  fS.oo 
TREVES.    Physical  Education  :  Its  Effects,  Methods,  Etc.  .75 
LIZARS.    The  Use  and  Abuse  of  Tobacco.  .40 
PARRISH.    Alcoholic  Inebriety.                                              Ji.oo 
ST.  CLAIR.    Medical  Latin.                                                      fi.oo 
SCHREINER.    Diet  Lists.    Pads  of  50.  .75 

NERVOUS  DISEASES. 

BEEVOR.  Diseases  of  the  Nervous  System  and  their  Treat- 
ment. >a-so 

GORDINIER.  The  Gross  and  Minute  Anatomy  of  the  Cen- 
tral Nervous  System.  With  many  original  Colored  and  other 
Illustrations.  Nearly  Ready.  Cloth,  16  oo;  Sheep,  f  7.00 

GOWERS.  Manual  of  Diseases  of  the  Nervous  System.  A 
Complete  Text-Book,  ad  Edition,  Revised,  Enlarged,  and  in  many 
parts  Rewritten.  With  many  new  Illustrations.  Two  volumes. 
Vol.  I.  Diseases  of  the  Nerves  and  Spinal  Cord.  Clo.  $3.00;  Sh.g4.oo 
Vol.  II.  Diseases  of  the  Brain  and  Cranial  Nerves;  General  and 
Functional  Disease.  Cloth,  $4.00;  Sheep,  $5.00 

GOWERS.    Syphilis  and  the  Nervous  System.  fi.oo 

GOWERS.  Diagnosis  of  Diseases  of  the  Brain,  ad  Edition. 
Illustrated.  >'-5° 

GOWERS.  Clinical  Lectures.  A  New  Volume  of  Essays  on  the 
Diagnosis,  Treatment,  etc.,  of  Diseases  of  the  Nervous  System.  $2.00 

GOWERS.  Epilepsy  and  Other  Chronic  Convulsive  Diseases, 
ad  Edition.  /*  Prttt. 

HOR8LEY.  The  Brain  and  Spinal  Cord.  The  Structure  and 
Functions  of.  Numerous  Illustrations. 


MEDICAL  BOOKS.  15 


OBERSTEINER.  The  Anatomy  of  the  Central  Nervous  Or- 
gans. A  Guide  to  the  Study  of  their  Structure  in  Health  and  Dis- 
ease. 198  Illustrations.  $5-5° 

ORMEROD.  Diseases  of  the  Nervous  System.  66  Wood  En- 
gravings. .  £1.00 

OSLER.    Cerebral  Palsies  of  Children.    A  Clinical  Study.    $2.00 

OSLER.    Chorea  and  Choreiform  Affections.  $2.00 

PRESTON.  Hysteria  and  Certain  Allied  Conditions.  Their 
Nature  and  Treatment.  Illustrated.  $2.00 

'WATSON.  Concussions.  An  Experimental  Study  of  Lesions  Aris- 
ing from  Severe  Concussions.  Paper  cover,  Ji.oo 

WOOD.    Brain  Work  and  Overwork.  .40 

NURSING. 

Special  Catalogue  of  Books  for  Nurses  sent  free  upon  application. 

BROWN.    Elementary  Physiology  for  Nurses.  .75 

CANFIELD.  Hygiene  of  the  Sick-Room.  A  Book  for  Nurses  and 
Others.  Being  a  Brief  Consideration  of  Asepsis,  Antisepsis,  Disinfec- 
tion?  Bacteriology,  Immunity,  Heating  and  Ventilation,  and  Kindred 
Subjects  for  the  Use  of  Nurses  and  Other  Intelligent  Women.  $1.25 

CULLING  WORTH.  A  Manual  of  Nursing,  Medical  and  Sur- 
gical. 3d  Edition  with  Illustrations.  .75 

CULLINGWORTH.  A  Manual  for  Monthly  Nurses.  sdEd.  .40 

CUFF.    Lectures  to  Nurses  on  Medicine.    New  Ed.  {1.25 

DOMVILLE.  Manual  for  Nurses  and  Others  Engaged  in  At- 
tending the  Sick.  8th  Edition.  With  Recipes  for  Sick-room  Cook- 
ery, etc.  .75 

FULLERTON,    Obstetric  Nursing.    41  Ills,    sth  Ed.          Ji.oo 

FULLERTON.  Nursing  in  Abdominal  Surgery  and  Diseases 
of  Women.  Comprising  the  Regular  Course  of  Instruction  at  the 
Training-School  of  the  Women's  Hospital,  Philadelphia.  2d  Edition. 
70  Illustrations.  $1.50 

GROFF.  Materia  Medica  for  Nurses.  With  Questions  for  Self-Ex- 
amination and  a  very  complete  Glossary.  Just  Ready.  tl-*5 

HUMPHREY.  A  Manual  for  Nurses.  Including  General 
Anatomy  and  Physiology,  Management  of  the  Sick  Room,  etc. 
i6th  Ed.  Illustrated.  Ji.oo 

SH  AWE.  Notes  for  Visiting  Nurses,  and  all  those  Interested 
in  the  Working  and  Organization  of  District,  Visiting,  or 
Parochial  Nurse  Societies.  With  an  Appendix  Explaining  the 
Organization  and  Working  of  Various  Visiting  and  District  Nurse  So- 
cieties, by  HELEN  C.  JENKS,  of  Philadelphia.  Ji.oo 

STARR.  The  Hygiene  of  the  Nursery.  Including  the  General 
Regimen  and  Feeding  of  Infants  and  Children,  and  the  Domestic  Man- 
agement of  the  Ordinary  Emergencies  of  Early  Life,  Massage,  etc.  6th 
Edition.  25  Illustrations.  £1.00 

TEMPERATURE  AND  CLINICAL  CHARTS.    See  page  6. 

VOSWINKEL.  Surgical  Nursing.  Second  Edition,  Enlarged. 
112  Illustrations.  Just  Ready.  $1.00 

WARD.     Notes  on  Massage.    Interleaved.  Paper  cover,  ji.oo 

OBSTETRICS. 

BAR.  Antiseptic  Midwifery.  The  Principles  of  Antiseptic  Meth- 
ods Applied  to  Obstetric  Practice.  Authorized  Translation  by 
HENRY  D.  FRY,  M.D..  with  an  Appendix  by  the  Author.  fi.oo 


1C  SUBJECT  CATALOGU*. 

CAZEAUX  AND  TARNIER.  Midwifery.  With  Appendix  by 
M  UNUB.  The  Theory  and  Practice  of  Obstetrics,  including  the  Dis- 
eases pi  Pregnancy  and  Parturition,  Obstetrical  Operations,  etc. 
8th  Edition.  Illustrated  by  Chromo- Lithographs,  Lithographs,  and 
other  full-page  Plates,  seven  of  which  are  beautifully  colored,  and 
numerous  Wood  Engravings.  Cloth,  £4.50  ;  Full  Leather,  $5.50 

DAVIS.  A  Manual  of  Obstetrics.  Being  a  Complete  Manual  for 
Physicians  and  Students,  pd  Enlarged  and  Revised  Edition.  With 
Colored  and  many  other  Illustrations.  In  Press. 

LANDIS.  Compend  of  Obstetrics.  6th  Edition,  Revised  by  WM. 
H.  WELLS,  Assistant  Demonstrator  of  Clinical  Obstetrics,  Jefferson 
Medical  College.  With  47  Illustrations,  .80;  Interleaved,  $1.25. 

SCHULTZE.  Obstetrical  Diagrams.  Being  a  series  of  ao  Col- 
ored Lithograph  Charts,  Imperial  Map  Size,  of  Pregnancy  and  Mid- 
wifery, with  accompanying  explanatory  (German)  text  illustrated 
by  Wood  Cuts,  ad  Revised  Edition. 

Price  in  Sheets,  $26.00;  Mounted  on  Rollers,  Muslin  Backs,  % 36.00 

STRAHAN.  Extra-Uterine  Pregnancy.  The  Diagnosis  and 
Treatment  of  Extra-Uterine  Pregnancy.  .75 

WINCKEL.  Text-Book  of  Obstetrics,  Including  the  Pathol- 
ogy and  Therapeutics  of  the  Puerperal  State.  Authorized 
Translation  by  J.  CUFTON  EDGAR,  A.M.,  M.D.  With  nearly  200  Illus- 
trations. Cloth,  $5.00;  Leather,  $6.00 

FULLERTON.    Obstetric  Nursing,     sth  Ed.    Illustrated,    fi.oo 

PATHOLOGY. 

BARLOW.    General  Pathology.    795  pages.    8vo.  fc.oo 

BLACKBURN.  Autopsies.  A  Manual  of  Autopsies  Designed  for 
the  Use  ot  Hospitals  for  the  Insane  and  other  Public  Institutions. 
Ten  full-page  Plates  and  other  Illustrations.  f«-»5 

BLODGETT.  Dental  Pathology.  By  ALBERT  N.  BLODGrrr. 
M.D.,  late  Professor  of  Pathology  and  Therapeutics,  Boston  Dental 
College.  33  Illustrations.  $1.25 

COPLIN.  Manual  of  Pathology.  Including  Bacteriology,  Technic 
of  Post-Mortems,  Mrthods  of  Pathologic  Research,  etc.  265  Illus- 
trations, many  of  which  are  original.  iamo.  $3-°° 

GILLI AM.     Pathology.  A  Hand-Book  for  Students.  47  Illus.     .75 

HALL.  Compend  of  General  Pathology  and  Morbid  Anatomy. 
91  very  fine  illustrations.  ad  Edition.  .80;  Interleaved,  $t. 2 5 

HEWLETT.     Manual  of  Bacteriology.     75  Illustrations.    $3.00 

VIRCHOW.  Post-Mortem  Examinations.  A  Description  and 
Explanation  of  the  Method  of  Performing  Them  in  the  Dead  House 
of  the  Berlin  Charity  Hospital,  with  Special  Reference  to  Medico- 
Leeal  Practice.  3d  Edition,'  with  Additions.  .75 

•WHITACRE.  Laboratory  Text-Book  of  Pathology.  With 
121  Illustrations.  I' -5° 

WILLIAMS.  Bacteriology.  A  Manual  for  Students.  78  Illus- 
trations. Just  Ready.  $'-5° 


PHARMACY. 

Special  Catalog**  of  Books  on  Pharmacy  tent /ret  upon  application. 
COBLENTZ.      Manual  of  Pharmacy.      A   New  and  Complete 

Text-Book  by  the  Professor  in  the  New  York  College  of  Pharmacy. 

ad  Edition,  Revised  and  Enlarged.  437  Illus.   Cloth.fc.so;  Sh.,$4.5O 


MEDICAL  BOOKS.  17 


BEASLEY.  Book  of  3100  Prescriptions.  Collected  from  the 
Practice  of  the  Most  Eminent  Physicians  and  Surgeons — English, 
French,  and  American.  A  Compendious  History  ot  the  Materia 
Medica,  Lists  of  the  Doses  of  all  the  Officinal  and  Established  Pre- 
parations, an  Index  of  Diseases  and  their  Remedies,  yth  Ed.  $2.00 

BEASLEY.  Druggists'  General  Receipt  Book.  Comprising 
a  Copious  Veterinary  Formulary,  Recipes  in  Patent  and  Proprietary 
Medicines,  Druggists'  Nostrums,  etc. ;  Perfumery  and  Cosmetics, 
Beverages,  Dietetic  Articles  and  Condiments,  Trade  Chemicals, 
Scientific  Processes,  and  many  Useful  Tables,  loth  Ed.  (2.00 

BEASLEY.  Pocket  Formulary.  A  Synopsis  of  the  British,  French, 
German,  and  United  States  Pharmacopoeias.  Comprising  Standard 
and  Approved  Formulae  for  the  Preparations  and  Compounds 
Employed  in  Medical  Practice.  I2th  Edition.  Just  Ready.  $2.00 

COBLENTZ.  The  Newer  Remedies.  3d  Edition,  Enlarged  and 
Revised.  Nearly  Ready. 

PROCTOR.  Practical  Pharmacy.  Lectures  on  Practical  Phar- 
macy. With  Wood  Engravings  and  32  Lithographic  Fac-simile 
Prescriptions,  jd  Edition,  Revised,  and  with  Elaborate  Tables  of 
Chemical  Solubilities,  etc.  $3-°o 

ROBINSON.  Latin  Grammar  of  Pharmacy  and  Medicine. 
3d  Edition.  With  elaborate  Vocabularies.  $1-75 

SAYRE.  Organic  Materia  Medica  and  Pharmacognosy.  An 
Introduction  to  the  Study  of  the  Vegetable  Kingdom  and  the  Vege- 
table and  Animal  Drugs.  Comprising  the  Botanical  and  Physical 
Characteristics,  Source,  Constituents,  and  Pharmacopeial  Prepar- 
ations. With  Chapters  on  Synthetic  Organic  Remedies,  Insects 
Injurious  to  Drugs,  and  Pharmacal  Botany.  A  Glossary  and  543 
Illustrations.  Second  Edition.  Preparing. 

SCOVILLE.  The  Art  of  Compounding.  Second  Edition,  Re- 
vised and  Enlarged.  Cloth,  $2. 50;  Sheep,  ^3. 50 

STEWART.  Compend  of  Pharmacy.  Based  upon  "  Reming- 
ton's Text-Book  of  Pharmacy."  sth  Edition,  Revised  in  Accord- 
ance with  the  U.  S.  Pharmacopoeia,  1890.  Complete  Tables  of 
Metric  and  English  Weights  and  Measures.  .80;  Interleaved,  $i. 25 

UNITED  STATES  PHARMACOPOEIA.  1890.  7th  Decennial 
Revision.  Cloth,  $2.50  (postpaid,  $2.77);  Sheep,  $3.00  (postpaid, 
$3.27);  Interleaved,  $4.00  (postpaid,  $4.50);  Printed  on  one  side  of 
page  only,  unbound,  $3.50  (postpaid,  £3.90). 

Select  Tables  from  the  U.  S.  P.  (1890).  Being  Nine  of  the  Most 
Important  and  Useful  Tables,  Printed  on  Separate  Sheets.  Care- 
fully put  up  in  patent  envelope.  .25 

POTTER.  Hand-Book  of  Materia  Medica,  Pharmacy,  and 
Therapeutics.  600  Prescriptions.1  7th  Ed.  do. ,$5.00;  Sh.,  $6.00 
***  Special  Catalogue  of  Books  on  Pharmacy  free  upon  application. 

PHYSICAL  DIAGNOSIS. 

BROWN.  Medical  Diagnosis.  A  Manual  of  Clinical  Methods. 
4th  Ed.  112  Illustrations.  Just  Ready,  Cloth,  $2.25 

FENWICK.  Medical  Diagnosis.  Sth  Edition.  Rewritten  and 
very  much  Enlarged.  135  Illustrations.  Cloth,  $2.50 

TYSON.  Hand-Book  of  Physical  Diagnosis.  For  Students  and 
Physicians.  By  the  Professor  of  Clinical  Medicine  in  the  University 
of  Pennsylvania.  Illus.  3d  Ed.,  Improved  and  Enlarged.  With 
Colored  and  other  Illustrations,  fust  Ready.  $1.50 

MEMMINGER.  Diagnosis  by  the  Urine.  2d  Ed.  24  Illus.  $1.00 
2 


18  SUBJECT  CATALOGUE. 

PHYSIOLOGY. 

BRUBAKER.  Compend  of  Physiology,  oth  Edition,  Revised 
and  Enlarged.  Illustrated.  Just  Ready.  .80:  Interleaved,  fi. 25 

KIRKE.  Physiology.  (isth  Authorized  Edition.  Dark-Red  Cloth.) 
A  Hand- Book  of  Physiology,  isth  Edition.  Revised,  Rearranged, 
•nd  Knlarged.  By  PKOF.  w.  D.  H  ALLIBUKTON,  of  Kings  College, 
London.  661  Illustrations,  some  o(  which  are  printed  in  colors. 
Just  Rrady.  Cloth.  $3.00;  Leather,  f 3.75 

LANDOIS.  A  Text-Book  of  Human  Physiology,  Including 
Histology  and  Microscopical  Anatomy,  with  Special  Reference  to 
the  Requirements  of  Practical  Medicine,  sth  American,  translated 
from  the  9th  German  Edition,  with  Additions  by  WM.  STIRLING, 
M.D..D.SC.  845  lllus.,  many  of  which  are  printed  in  colors.  In  frtst. 

STARLING.    Elements  of  Human  Physiology,    too  Ills.   $1.00 

STIRLING.  Outlines  of  Practical  Physiology.  Including 
Chemical  and  Experimental  Physiology,  with  Special  Reference  to 
Practical  Medicine.  3d  Edition.  289  Illustrations.  $2.00 

TYSON.     Cell  Doctrine.     Its  History  and  Present  Slate.        $1.50 

YEO.  Manual  of  Physiology.  A  Text- Book  for  Students  of 
Medicine.  By  GKKALD  K.  YBO,  M.D.,  P.KC.S.  3d  Edition.  354 
Illustrations  and  a  Glossary.  Cloth,  fa. 50  ;  Leather,  $3.00 

PRACTICE. 

BEALE.    On  Slight  Ailments;  their  Nature  and  Treatment. 

sd  Edition,  Enlarged  and  Illustrated.  $'-»5 

CHARTERIS.      Practice  of  Medicine.    6th  Edition.  fa.oo 

FOWLER.      Dictionary  of    Practical    Medicine.      By  various 

writers.  An  Encyclopaedia  of  Medicine.  Clo.,f3.oo;   Half  Mor.  $4.00 

HUGHES.    Compend  of  the  Practice  of  Medicine,    sth  Edition, 

Revised  and  Enlarged. 

Part  I.  Continued,  Eruptive,  and  Periodical  Fevers,  Diseases  of  the 
Stomach,  Intestines,  Peritoneum,  Biliary  Passages,  Liver,  Kid- 
neys, etc.,  and  General  Diseases,  etc. 

Part  II.  Diseases  of  the  Respiratory  System,  Circulatory  System, 
and  Nervous  System;  Diseases  of  the  Blood,  etc. 

Price  of  each  part,  .80;  Interleaved,  $1.25 

Physician's  Edition.  In  one  volume,  including  the  above  two 
parts,  a  Section  on  Skin  Diseases,  and  an  Index,  sth  Revised, 
Enlarged  Edition.  568  pp.  Full  Morocco,  Gilt  Edge,  $2.35 

ROBERTS.  The  Theory  and  Practice  of  Medicine.  The 
Sections  on  Treatment  are  especially  exhaustive.  9th  Edition, 
with  Illustrations.  Cloth,  $4.50;  Leather,  f  5.50 

TAYLOR.    Practice  of  Medicine,    sth  Edition.  Cloth,  $4.00 

TYSON.  The  Practice  of  Medicine.  By  JAMBS  TYSON,  M.D., 
Professor  of  Clinical  Medicine  in  the  University  of  Pennsylvania. 
A  Complete  Systematic  Text-book  with  Special  Reference  to  Diag- 
nosis and  Treatment.  Illustrated.  8vo. 

Cloth,  f  5. 50;  Leather,  $650 :  Half  Russia,  $7. 50 

PRESCRIPTION  BOOKS. 

BEASLEY.  Book  of  3100  Prescriptions.  Collected  from  the 
Practice  of  the  Most  Eminent  Physicians  and  Surgeons — English, 
French,  and  American.  A  Compendious  History  of  the  Materia, 
Medica,  Lists  of  the  Doses  of  all  Officinal  and  Established  Prepara- 
tions, and  an  Index  of  Diseases  and  their  Remedies.  7th  Ed.  fs.oo 


MEDICAL  BOOKS.  19 


BEASLEY.  Druggists'  General  Receipt  Book.  Comprising 
a  Copious  Veterinary  Formulary,  Recipes  in  Patent  and  Proprie- 
tary Medicines,  Druggists'  Nostrums,  etc.  ;  Perfumery  and  Cos- 
metics, Beverages,  Dietetic  Articles  and  Condiments,  Trade  Chem- 
icals, Scientific  Processes,  and  an  Appendix  of  Useful  Tables, 
loth  Edition,  Revised.  $2.00 

BEASLEY.  Pocket  Formulary.  A  Synopsis  of  the  British,  French, 
German,  and  United  States  Pharmacopoeias  and  the  chief  unofficial 
Formularies.  I2th  Edition.  Just  Ready.  $2.00 

WYTHE.     Dose  and  Symptom  Book.    Containing  the  Doses  and 

Uses  of  all  the  Principal  Articles  of  the  Materia  Medica.     iyth  Ed. 

Cloth,  .75 ;  Leather,  with  Tucks  and  Pocket,  $1.00 

SKIN. 

BULKLEY.    The  Skin  in  Health  and  Disease.    Illustrated.    .40 

CROCKER.  Diseases  of  the  Skin.  Their  Description,  Pathol- 
ogy, Diagnosis,  and  Treatment,  with  Special  Reference  to  the  Skin 
Eruptions  of  Children.  92  Illus.  sd  Edition.  Preparing. 

IMPEY.     Leprosy.    37  Plates.     8vo.  $3.50 

SCHAMBERG.  Diseases  of  the  Skin.  99  Illustrations.  Being 
No.  16?  Quiz-Compend?  Series.  Cloth,  .80;  Interleaved,  $1. 25 

VAN  HARLINGEN.  On  Skin  Diseases.  A  Practical  Manual 
of  Diagnosis  and  Treatment,  with  special  reference  to  Differential 
Diagnosis.  3d  Edition,  Revised  and  Enlarged.  With  Formulae 
and  60  Illustrations,  some  of  which  are  printed  in  colors.  12.75 

SURGERY  AND  SURGICAL  DIS- 
EASES (see  also  Urinary  Organs). 

CRIPPS.    Ovariotomy  and  Abdominal  Surgery.    Illus.      $8.00 

DEAVER.  Appendicitis,  Its  Symptoms,  Diagnosis,  Pathol- 
ogy, Treatment,  and  Complications.  Elaborately  Illustrated 
with  Colored  Plates  and  other  Illustrations.  Cloth,  $3.50 

DEAVER.  Surgical  Anatomy.  With  400  Illustrations,  Drawn  by 
Special  Artists  from  Dissections  made  for  the  Purpose.  In  Prtst. 

DULLES.  What  to  Do  First  in  Accidents  and  Poisoning. 
5th  Edition.  New  Illustrations.  $1.00 

HACKER.  Antiseptic  Treatment  of  Wounds,  According  to 
the  Method  in  Use  at  Professor  Billroth's  Clinic,  Vienna.  .50 

HAMILTON.  Lectures  on  Tumors,  from  a  Clinical  Stand- 
point. Third  Edition,  Revised,  with  New  Illustrations.  $1-25 

HEATH.  Minor  Surgery  and  Bandaging.  loth  Ed.,  Revised 
and  Enlarged.  158  Illustrations,  62  Formulae,  Diet  List,  etc.  £1.25 

HEATH.  Injuries  and  Diseases  of  the  Jaws.  4th  Edition. 
187  Illustrations.  $4-5° 

HEATH.  Lectures  on  Certain  Diseases  of  the  Jaws.  64  Illus- 
trations. Boards,  .50 

HORWITZ.  Compend  of  Surgery  and  Bandaging,  including 
Minor  Surgery,  Amputations,  Fractures,  Dislocations,  Surgical  Dis- 
eases, and  the  Latest  Antiseptic  Rules,  etc.,  with  Differential  Diagno- 
sis and  Treatment.  '  sth  Edition,  very  much  Enlarged  and  Rear- 
ranged. 167  Illustrations,_g8  Formulae.  Clo.,  .80 ;  Interleaved,  $1.25 


SUBJECT  CATALOGUE. 


JACOBSON.  Operations  of  Surgery.  Over  aoo  Illustrations. 

Cloth,  $3.00 ;  Leather,  $4.00 

JACOBSON.  Diseases  of  the  Male  Organs  of  Generation. 
88  Illustrations.  |6  oo 

MACREADY.  A  Treatise  on  Ruptures.  24  Full-page  Litho- 
graphed Plates  and  Numerous  Wood  Engravings.  Cloth,  $6.00 

MAYLARD.  Surgery  of  the  Alimentary  Canal.  134  lllus.  $7.50 

MOULLIN.  Text-Book  of  Surgery.  With  Special  Reference  to 
Treatment.  3d  American  Edition.  Revised  and  edited  by  JOHN  B. 
HAMILTON,  M.D.,  LL.D..  Professor  of  the  Principles  of  Surgery  and 
Clinical  Surgery,  Rush  Medical  College,  Chicago.  623  Illustrations, 
over  200  of  which  are  original,  and  many  of  which  are  printed  in 
colors.  Handsome  Cloth,  $6.00;  Leather,  % 7.00 

"  The  aim  to  make  this  valuable  treatise  practical  by  giving  special 

attention  to   questions  of  treatment  has  been  admirably  carried  out. 

Many  a  reader  will  consult  the  work  with  a  feeling  of  satisfaction  that 

his  wants  have  been  understood,  and  that  they  have  been  intelligently 

met." —  The  American  Journal  of  Medical  Science. 

ROBERTS.  Fractures  of  the  Radius.  A  Clinical  and  Patho- 
logical Study.  33  Illustrations.  $1.00 

SMITH.  Abdominal  Surgery.  Being  a  Systematic  Description  ol 
all  the  Principal  Operations.  224  lllus.  6th  Ed.  a  Vols.  Clo.,  f 10.00 

SWAIN      Surgical  Emergencies.     Fifth  Edition.         Cloth,  $1.75 

VOSWINKEL.  Surgical  Nursing.  Second  Edition,  Revised  and 
Enlarged,  tn  Illustrations.  Just  Ready.  fi.oo 

WALSHAM.  Manual  of  Practical  Surgery.  6th  Ed.,  Re- 
vised and  Enlarged.  With  410  Engravings.  f  3  °° 

WATSON.  On  Amputations  of  the  Extremities  and  Their 
Complications.  250  Illustrations.  1 5-5° 

THROAT   AND    NOSE   (see  also  Ear). 

COHEN.    The  Throat  and  Voice.     Illustrated.  .40 

HALL.      Diseases   of  the    Nose    and    Throat.    Two   Colored 

Plates  and  59  Illustrations.  $2.50 

HOLLOPETER.     Hay  Fever.     Its  Successful  Treatment.      Ji.co 

HUTCHINSON.    The  Nose  and  Throat.    Including  the  Nose, 

Naso- Pharynx,  Pharynx,  and   Larynx.     Illustrated  by   Lithograph 

Plates  and  40  other  Illustrations.     2d  Edition.  In  Press. 

MACKENZIE.  Pharmacopoeia  of  the  London  Hospital  for 
Dis.  of  the  Throat.  $th  Ed.,  Revised  by  Dr.  F.  G.  HAKVBY.  $1.00 

McBRIDE.  Diseases  of  the  Throat,  Nose,  and  Ear.  A  Clinical 
Manual.  With  colored  lllus.  from  original  drawings.  2d  Ed.  Jfi.oo 

POTTER.  Speech  and  its  Defects.  Considered  Physiologically, 
Pathologically,  and  Remedially.  Ji.oo 

URINE  AND  URINARY  ORGANS. 

ACTON.  The  Functions  and  Disorders  of  the  Reproductive 
Organs  in  Childhood,  Youth,  Adult  Age,  and  Advanced  Life, 
Considered  in  their  Physiological,  Social,  and  Moral  Relations. 
8th  Edition.  fi-75 

ALLEN.    Albuminous  and  Diabetic  Urine.    lllus.  £2.25 


MEDICAL  BOOKS.  21 


BROCKBANK.    Gall  Stone*.  $2.35 

BEALE.  One  Hundred  Urinary  Deposits.  On  eight  sheets, 
for  the  Hospital,  Laboratory,  or  Surgery.  Paper,  $2.00 

HOLLAND.  The  Urine,  the  Gastric  Contents,  the  Common 
Poisons,  and  the  Milk.  Memoranda,  Chemical  and  Microscopi- 
cal, for  Laboratory  Use.  Illustrated  and  Interleaved.  5th  Ed.  $1.00 

JACOBSON.  Diseases  of  the  Male  Organs  of  Generation.  88 
Illustrations.  $6.00 

MEMMINGER.    Diagnosis  by  the  Urine.   21!  Ed.  24  Illus.  $1.00 

MORRIS.  Renal  Surgery,  with  Special  Reterence  to  Stone  in  the 
Kidney  and  Ureter  and  to  the  Surgical  Treatment  of  Calculous 
Anuria.  Illustrated.  $2.00. 

MOULLIN.  Enlargement  of  the  Prostate.  Its  Treatment  and 
Radical  Cure.  2d  Edition.  Illustrated.  In  Press. 

MOULLIN.  Inflammation  of  the  Bladder  and  Urinary  Fever. 
Octavo.  Just  Ready,  |i-5o 

THOMPSON.    Diseases  of  the  Urinary  Organs.   8th  Ed.  $3.00 

TYSON.  Guide  to  Examination  of  the  Urine.  For  the  Use  of 
Physicians  and  Students.  With  Colored  Pla<e  and  Numerous  Illus- 
trations engraved  on  wood.  9th  Edition,  Revised.  t*-*S 

VAN  NUYS.  Chemical  Analysis  of  Healthy  and  Diseased 
Urine,  Qualitative  and  Quantitative.  39  Illustrations.  £1.00 

VENEREAL  DISEASES. 

COOPER.     Syphilis,    ad    Edition,  Enlarged  and  Illustrated  with 

20  full-page  Plates.  $5-°° 

GOWERS.    Syphilis  and  the  Nervous  System.  i.oo 

VETERINARY. 

ARMATAGE.  The  Veterinarian's  Pocket  Remembrancer. 
Being  Concise  Directions  for  the  Treatment  of  Urgent  or  Rare  Cases, 
Embracing  Semeiology,  Diagnosis,  Prognosis,  Surgery,  Treatment, 
etc.  2tl  Edition.  Boards,  %i  .00 

BALLOU.  Veterinary  Anatomy  and  Physiology.  29  Graphic 
Illustrations.  .80;  Interleaved,  $1.25 

TUSON.  Veterinary  Pharmacopoeia.  Including  the  Outlines  of 
Materia  Medica  and  Therapeutics.  5th  Edition.  $ 2.25 

WOMEN,  DISEASES  OF. 

BYFORD  (H.  T.).  Manual  of  Gynecology.  Second  Edition, 
Revised  and  Enlarged  by  100  pages.  With  341  Illustrations,  many 
oi  which  are  from  original  drawings.  $ 3.00 

BYFORD    (W.  H.).    Diseases  of  Women.    4th  Edition.    306 

Illustrations.  Cloth,  $2.00 

DUHRSSEN.  A  Manual  of  Gynecological  Practice.  105 
Illustrations.  f'-So 

LEWERS.    Diseases  of  Women.    146  Illus.    sth  Ed.  £2.50 

WELLS.  Compend  of  Gynecology.    Illustrated. 

.80;   Interleaved,  $1.25 

PULLERTON.  Nursing  in  Abdominal  Surgery  and  Diseases 
of  Women.  2d  Edition.  70  Illustrations.  11.50 


SUBJECT  CATALOGUE. 


COMPENDS. 


from    The  fiimthrrn    Clinic. 

"  We  know  of  no  series  of  books  issued  by  any  house  that  so  fully 
meets  our  approval  as  these  TQuu-CompendsT.  They  are  well  ar- 
ranged, hill,  and  concise,  and  are  really  the  best  line  oi  text-books  that 
could  be  found  for  either  student  or  practitioner." 


BLAKISTON'S  ?QUIZ-COMPENDS? 

The  Best  Series  of  Manuals  for  the  Use  of  Students. 
Price  of  each.  Cloth,  .80.         Interleaved,  for  taking  Notes,  $1.25. 

49*  These  Compends  are  based  on  the  most  popular  text-books 
and  the  lectures  of  prominent  professors,  and  are  kept  constantly  re- 
vised, so  that  they  may  thoroughly  represent  the  present  state  of  the 
subjects  upon  which  they  treat. 

49*  The  authors  have  had  large  experience  as  Quiz-Masters  and 
attaches  of  colleges,  and  are  well  acquainted  with  the  wants  of  student*. 

49*  They  are  arranged  in  the  most  approved  form,  thorough  and 
concise,  containing  over  600  fine  illustrations,  inserted  wherever  they 
could  be  used  to  advantage. 

49*  Can  be  used  by  students  ot  any  college. 

49*  They  contain  information  nowhere  else  collected  in  such  a 
condensed,  practical  shape.  Illustrated  Circular  free. 

No.  i.  POTTER.  HUMAN  ANATOMY.  Sixth  Revised  and 
Enlarged  Edition.  Including  Visceral  Anatomy.  Can  be  used 
with  either  Morris's  or  Gray's  Anatomy.  117  Illustrations  and  16 
Lithographic  Plates  of  Nerves  and  Arteries,  with  Explanatory 
Tables,  etc.  By  SAMUEL  O.  L.  POTTER,  M.D.,  Professor  of  the 
Practice  of  Medicine,  Cooper  Medical  College,  San  Francisco ;  late 
A.  A.  Surgeon,  U.  S.  Army. 

No.  a.  HUGHES.  PRACTICE  OF  MEDICINE.  Parti.  Fifth 
Edition,  Enlarged  and  Improved.  By  DANIEL  E.  HUGHES,  M.D., 
Physician-in-Chief,  Philadelphia  Hospital,  late  Demonstrator  ol 
Clinical  Medicine,  Jefferson  Medical  College,  Phila. 

No.  3.  HUGHES.  PRACTICE  OF  MEDICINE.  Part  II. 
Fifth  Edition,  Revised  and  Improved.  Same  author  as  No.  a. 

No.  4.  BRUBAKER.  PHYSIOLOGY.  Ninth  Edition,  with 
new  Illustrations  and  a  table  of  Physiological  Constants.  Enlarged 
and  Revised.  By  A.  P.  BKUBAKER,  M.D.,  Professor  of  Physiology 
and  General  Pathology  in  the  Pennsylvania  College  of  Dental 
Surgery;  Adjunct  Professor  of  Physiology,  Jefferson  Medical 
College,  Philadelphia,  etc. 

No.  5.  LANDIS.  OBSTETRICS.  Sixth  Edition.  By  HBNRT  G. 
LANDIS,  M.D.  Revised  and  Edited  by  WM.  H.  WELLS,  M.D., 
Instructor  of  Obstetrics,  Jefferson  Medical  College,  Philadelphia. 
Enlarged.  47  Illustrations. 

No.  6.  POTTER.  MATERIA  MEDICA,  THERAPEUTICS, 
AND  PRESCRIPTION  WRITING.  Sixth  Revised  Edition 
(U.  S.  P.  1890).  By  SAMUEL  O.  L.  POTTBK,  M.D.,  Professor  of 
Practice,  Cooper  Medical  College,  San  Francisco  ;  late  A.  A.  Sur- 
geon, U.  S.  Army. 


MEDICAL  BOOKS. 


PQUIZ-COMPENDS  ?— Continued. 

No.  7.  WELLS.     GYNECOLOGY.     By  WM.  H.  WELLS,  M  D., 

Instructor  of  Obstetrics,  Jefferson  College,  Philadelphia.  150  Illus- 
trations. 

No.  8.  GOULD  AND  PYLE.  DISEASES  OF  THE  EYE 
AND  REFRACTION.  A  New  Book.  Including  Treatment 
and  Surgery,  and  a  Section  on  Local  Therapeutics.  By  GBORGS 
M.  GOULD,  M.D.,  and  VV.  L  PYLB,  M.D.  With  Formulae, Glossary, 
Tables,  and  HI  Illustrations,  several  of  which  are  Colored. 

No.  9.  HORWITZ.  SURGERY,  Minor  Surgery,  and  Bandag- 
ing. Fifth  Edition,  Enlarged  and  Improved.  By  ORVILLB 
HOKWITZ,  B.  s-,  M.O.,  Clinical  Professor  of  Genito-Urinary  Surgery 
and  Venereal  Diseases  in  Jefferson  Medical  College  ;  Surgeon  to 
Philadelphia  Hospital,  etc.  With  98  Formulae  and  71  Illustrations. 

No.  10.  LEFFMANN.     MEDICAL    CHEMISTRY.      Fourth 

Edition.  Including  Urinalysis,  Animal  Chemistry,  Chemistry  of 
Milk,  Blood,  Tissues,  the  Secretions,  etc.  By  HBNRY  LEFFMANN. 
M.D.,  Professor  of  Chemistry  in  Pennsylvania  College  of  Dental 
Surgery  and  in  the  Woman's  Medical  College,  Philadelphia. 

No.  ii.  STEWART.  PHARMACY.  Fifth  Edition.  Based  upon 
Prof.  Remington's  Text-Book  of  Pharmacy.  By  K.  E.  STEWART, 
M.D.,  PH.G.,  late  Quiz-Master  in  Pharmacy  and  Chemistry,  Phila- 
delphia College  of  Pharmacy ;  Lecturer  at  Jefferson  Medical 
College.  Carefully  revised  in  accordance  with  the  new  U.  S.  P. 

No.  xa.  BALLOU.  VETERINARY  ANATOMY  AND  PHY- 
SIOLpGY.  Illustrated.  By  WM.  R.  BALLOU,  M.D.,  Professor 
of  Equine  Anatomy  at  New  York  College  of  Veterinary  Surgeons ; 
Physician  to  Bellevue  Dispensary,  etc.  29  graphic  Illustrations. 

No.  13.  WARREN.  DENTAL  PATHOLOGY  AND  DEN- 
TAL MEDICINE.  Third  Edition,  Illustrated.  Containing 
a  Section  on  Emergencies.  By  GEO.  W.  WARREN,  D.D.S.,  Chiel 
ot  Clinical  Staff,  Pennsylvania  College  of  Dental  Surgery. 

No.  11.  HATFIELD.  DISEASES  OF  CHILDREN.  Second 
Edition.  Colored  Plate.  By  MARCUS  P.  HATPIBLD,  Profes- 
sor of  Diseases  of  Children,  Chicago  Medical  College. 

No.  15.  HALL.  GENERAL  PATHOLOGY  AND  MORBID 
ANATOMY.  91  Illustrations.  By  H.  NBWBERRY  HALL,  PH.G., 
M.D.,  late  Professor  of  Pathology,  Chicago  Post-Graduate  Medi- 
cal School.  Second  Edition. 

No.  16.  DISEASES  OF  THE  SKIN.  By  JAY  T.  SCHAMBBRG, 
M.D.,  Instructor  in  Skin  Diseases,  Philadelphia  Polyclinic.  With 
99  handsome  Illustrations. 

Price,  each,  Cloth,  .80.  Interleaved,  for  taking  Notes,  $1.25. 

In  preparing,  revising,  and  improving  BLAKISTON'S  T  Quiz-CoM- 
PENDS  J  the  particular  wants  of  the  student  have  always  been  kept  in 
mind. 

Careful  attention  has  been  given  to  the  construction  of  each  sentence, 
and  while  the  books  will  be  found  to  contain  an  immense  amount  of 
knowledge  in  small  space,  they  will  likewise  be  found  easy  reading ; 
there  is  no  stilted  repetition  of  words ;  the  style  is  clear,  lucid,  and  dis- 
tinct. The  arrangement  of  subjects  is  systematic  and  thorough  ;  there 
Is  a  reason  for  every  word.  They  contain  over  600  illustrations. 


Morris' 
Anatomy 

Second   Edition, 
Revised  and   Enlarged. 

790  Illustrations,  of  which  many 

51  rp   in    Cnlnr«s_ 


are  in  Colors. 


Royal  Octavo.    Cloth,  $6.00  ;  Sheep,  $7.00  ; 
Half  Russia,  $8.00. 


From  The  Medical  Record,  New  York. 

"  The  reproach  that  the  English  language  can  boast  of  no 
treatise  on  anatomy  deserving  to  be  ranked  with  the  masterly 
works  of  Henle,  Luschka,  Hyrtl,  and  others,  is  fast  losing 
its  force.  During  the  past  few  years  several  works  of  great 
merit  have  appeared,  and  among  these  Morris's  "  Anatomy  " 
seems  destined  to  take  first  place  in  disputing  the  palm  in 
anatomical  fields  with  the  German  classics.  The  nomencla- 
ture, arrangement,  and  entire  general  character  resemble 
strongly  those  of  the  above-mentioned  handbooks,  while  in 
the  beauty  and  profuseness  of  its  illustrations  it  surpasses 
them.  .  .  .  The  ever-growing  popularity  of  the  book 
with  teachers  and  students  is  an  index  of  its  value,  and  it 
may  safely  be  recommended  to  all  interested." 


*»*  Handsome  Descriptive  Circular,  with 
Sample  Pages  and  Colored  Illustrations, 
will  be  sent  free  upon  application. 


A     000414516     5 


